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/en/sql-reference/functions/date-time-functions 45 Dates and Times

Functions for Working with Dates and Times

Most functions in this section accept an optional time zone argument, e.g. Europe/Amsterdam. In this case, the time zone is the specified one instead of the local (default) one.

Example

SELECT
    toDateTime('2016-06-15 23:00:00') AS time,
    toDate(time) AS date_local,
    toDate(time, 'Asia/Yekaterinburg') AS date_yekat,
    toString(time, 'US/Samoa') AS time_samoa

┌────────────────time─┬─date_local─┬─date_yekat─┬─time_samoa──────────┐
│ 2016-06-15 23:00:00 │ 2016-06-15 │ 2016-06-16 │ 2016-06-15 09:00:00 │
└─────────────────────┴────────────┴────────────┴─────────────────────┘

makeDate

Creates a Date

  • from a year, month and day argument, or
  • from a year and day of year argument.

Syntax

makeDate(year, month, day);
makeDate(year, day_of_year);

Alias:

  • MAKEDATE(year, month, day);
  • MAKEDATE(year, day_of_year);

Arguments

Returned value

  • A date created from the arguments.

Type: Date.

Example

Create a Date from a year, month and day:

SELECT makeDate(2023, 2, 28) AS Date;

Result:

┌───────date─┐
│ 2023-02-28 │
└────────────┘

Create a Date from a year and day of year argument:

SELECT makeDate(2023, 42) AS Date;

Result:

┌───────date─┐
│ 2023-02-11 │
└────────────┘

makeDate32

Like makeDate but produces a Date32.

makeDateTime

Creates a DateTime from a year, month, day, hour, minute and second argument.

Syntax

makeDateTime(year, month, day, hour, minute, second[, timezone])

Arguments

Returned value

  • A date with time created from the arguments.

Type: DateTime.

Example

SELECT makeDateTime(2023, 2, 28, 17, 12, 33) AS DateTime;

Result:

┌────────────DateTime─┐
│ 2023-02-28 17:12:33 │
└─────────────────────┘

makeDateTime64

Like makeDateTime but produces a DateTime64.

Syntax

makeDateTime64(year, month, day, hour, minute, second[, fraction[, precision[, timezone]]])

timestamp

Converts the first argument 'expr' to type DateTime64(6). If a second argument 'expr_time' is provided, it adds the specified time to the converted value.

Syntax

timestamp(expr[, expr_time])

Alias: TIMESTAMP

Arguments

  • expr - Date or date with time. Type: String.
  • expr_time - Optional parameter. Time to add. String.

Examples

SELECT timestamp('2023-12-31') as ts;

Result:

┌─────────────────────────ts─┐
│ 2023-12-31 00:00:00.000000 │
└────────────────────────────┘

SELECT timestamp('2023-12-31 12:00:00', '12:00:00.11') as ts;

Result:

┌─────────────────────────ts─┐
│ 2024-01-01 00:00:00.110000 │
└────────────────────────────┘

Returned value

timeZone

Returns the timezone of the current session, i.e. the value of setting session_timezone. If the function is executed in the context of a distributed table, then it generates a normal column with values relevant to each shard, otherwise it produces a constant value.

Syntax

timeZone()

Alias: timezone.

Returned value

  • Timezone.

Type: String.

Example

SELECT timezone()

Result:

┌─timezone()─────┐
│ America/Denver │
└────────────────┘

See also

serverTimeZone

Returns the timezone of the server, i.e. the value of setting timezone. If the function is executed in the context of a distributed table, then it generates a normal column with values relevant to each shard. Otherwise, it produces a constant value.

Syntax

serverTimeZone()

Alias: serverTimezone.

Returned value

  • Timezone.

Type: String.

Example

SELECT serverTimeZone()

Result:

┌─serverTimeZone()─┐
│ UTC              │
└──────────────────┘

See also

toTimeZone

Converts a date or date with time to the specified time zone. Does not change the internal value (number of unix seconds) of the data, only the value's time zone attribute and the value's string representation changes.

Syntax

toTimezone(value, timezone)

Alias: toTimezone.

Arguments

  • value — Time or date and time. DateTime64.
  • timezone — Timezone for the returned value. String. This argument is a constant, because toTimezone changes the timezone of a column (timezone is an attribute of DateTime* types).

Returned value

  • Date and time.

Type: DateTime.

Example

SELECT toDateTime('2019-01-01 00:00:00', 'UTC') AS time_utc,
    toTypeName(time_utc) AS type_utc,
    toInt32(time_utc) AS int32utc,
    toTimeZone(time_utc, 'Asia/Yekaterinburg') AS time_yekat,
    toTypeName(time_yekat) AS type_yekat,
    toInt32(time_yekat) AS int32yekat,
    toTimeZone(time_utc, 'US/Samoa') AS time_samoa,
    toTypeName(time_samoa) AS type_samoa,
    toInt32(time_samoa) AS int32samoa
FORMAT Vertical;

Result:

Row 1:
──────
time_utc:   2019-01-01 00:00:00
type_utc:   DateTime('UTC')
int32utc:   1546300800
time_yekat: 2019-01-01 05:00:00
type_yekat: DateTime('Asia/Yekaterinburg')
int32yekat: 1546300800
time_samoa: 2018-12-31 13:00:00
type_samoa: DateTime('US/Samoa')
int32samoa: 1546300800

See Also

timeZoneOf

Returns the timezone name of DateTime or DateTime64 data types.

Syntax

timeZoneOf(value)

Alias: timezoneOf.

Arguments

Returned value

  • Timezone name.

Type: String.

Example

SELECT timezoneOf(now());

Result:

┌─timezoneOf(now())─┐
│ Etc/UTC           │
└───────────────────┘

timeZoneOffset

Returns the timezone offset in seconds from UTC. The function daylight saving time and historical timezone changes at the specified date and time into account. The IANA timezone database is used to calculate the offset.

Syntax

timeZoneOffset(value)

Alias: timezoneOffset.

Arguments

Returned value

  • Offset from UTC in seconds.

Type: Int32.

Example

SELECT toDateTime('2021-04-21 10:20:30', 'America/New_York') AS Time, toTypeName(Time) AS Type,
       timeZoneOffset(Time) AS Offset_in_seconds, (Offset_in_seconds / 3600) AS Offset_in_hours;

Result:

┌────────────────Time─┬─Type─────────────────────────┬─Offset_in_seconds─┬─Offset_in_hours─┐
│ 2021-04-21 10:20:30 │ DateTime('America/New_York') │            -14400 │              -4 │
└─────────────────────┴──────────────────────────────┴───────────────────┴─────────────────┘

toYear

Returns the year component (AD) of a date or date with time.

Syntax

toYear(value)

Alias: YEAR

Arguments

Returned value

  • The year of the given date/time

Type: UInt16

Example

SELECT toYear(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toYear(toDateTime('2023-04-21 10:20:30'))─┐
│                                      2023 │
└───────────────────────────────────────────┘

toQuarter

Returns the quarter (1-4) of a date or date with time.

Syntax

toQuarter(value)

Alias: QUARTER

Arguments

Returned value

  • The quarter of the year (1, 2, 3 or 4) of the given date/time

Type: UInt8

Example

SELECT toQuarter(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toQuarter(toDateTime('2023-04-21 10:20:30'))─┐
│                                            2 │
└──────────────────────────────────────────────┘

toMonth

Returns the month component (1-12) of a date or date with time.

Syntax

toMonth(value)

Alias: MONTH

Arguments

Returned value

  • The month of the year (1 - 12) of the given date/time

Type: UInt8

Example

SELECT toMonth(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toMonth(toDateTime('2023-04-21 10:20:30'))─┐
│                                          4 │
└────────────────────────────────────────────┘

toDayOfYear

Returns the number of the day within the year (1-366) of a date or date with time.

Syntax

toDayOfYear(value)

Alias: DAYOFYEAR

Arguments

Returned value

  • The day of the year (1 - 366) of the given date/time

Type: UInt16

Example

SELECT toDayOfYear(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toDayOfYear(toDateTime('2023-04-21 10:20:30'))─┐
│                                            111 │
└────────────────────────────────────────────────┘

toDayOfMonth

Returns the number of the day within the month (1-31) of a date or date with time.

Syntax

toDayOfMonth(value)

Aliases: DAYOFMONTH, DAY

Arguments

Returned value

  • The day of the month (1 - 31) of the given date/time

Type: UInt8

Example

SELECT toDayOfMonth(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toDayOfMonth(toDateTime('2023-04-21 10:20:30'))─┐
│                                              21 │
└─────────────────────────────────────────────────┘

toDayOfWeek

Returns the number of the day within the week of a date or date with time.

The two-argument form of toDayOfWeek() enables you to specify whether the week starts on Monday or Sunday, and whether the return value should be in the range from 0 to 6 or 1 to 7. If the mode argument is omitted, the default mode is 0. The time zone of the date can be specified as the third argument.

Mode First day of week Range
0 Monday 1-7: Monday = 1, Tuesday = 2, ..., Sunday = 7
1 Monday 0-6: Monday = 0, Tuesday = 1, ..., Sunday = 6
2 Sunday 0-6: Sunday = 0, Monday = 1, ..., Saturday = 6
3 Sunday 1-7: Sunday = 1, Monday = 2, ..., Saturday = 7

Syntax

toDayOfWeek(t[, mode[, timezone]])

Alias: DAYOFWEEK.

Arguments

  • t - a Date, Date32, DateTime or DateTime64
  • mode - determines what the first day of the week is. Possible values are 0, 1, 2 or 3. See the table above for the differences.
  • timezone - optional parameter, it behaves like any other conversion function

The first argument can also be specified as String in a format supported by parseDateTime64BestEffort(). Support for string arguments exists only for reasons of compatibility with MySQL which is expected by certain 3rd party tools. As string argument support may in future be made dependent on new MySQL-compatibility settings and because string parsing is generally slow, it is recommended to not use it.

Returned value

  • The day of the week (1-7), depending on the chosen mode, of the given date/time

Example

The following date is April 21, 2023, which was a Friday:

SELECT
    toDayOfWeek(toDateTime('2023-04-21')),
    toDayOfWeek(toDateTime('2023-04-21'), 1)

Result:

┌─toDayOfWeek(toDateTime('2023-04-21'))─┬─toDayOfWeek(toDateTime('2023-04-21'), 1)─┐
│                                     5 │                                        4 │
└───────────────────────────────────────┴──────────────────────────────────────────┘

toHour

Returns the hour component (0-24) of a date with time.

Assumes that if clocks are moved ahead, it is by one hour and occurs at 2 a.m., and if clocks are moved back, it is by one hour and occurs at 3 a.m. (which is not always exactly when it occurs - it depends on the timezone).

Syntax

toHour(value)

Alias: HOUR

Arguments

Returned value

  • The hour of the day (0 - 23) of the given date/time

Type: UInt8

Example

SELECT toHour(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toHour(toDateTime('2023-04-21 10:20:30'))─┐
│                                        10 │
└───────────────────────────────────────────┘

toMinute

Returns the minute component (0-59) a date with time.

Syntax

toMinute(value)

Alias: MINUTE

Arguments

Returned value

  • The minute of the hour (0 - 59) of the given date/time

Type: UInt8

Example

SELECT toMinute(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toMinute(toDateTime('2023-04-21 10:20:30'))─┐
│                                          20 │
└─────────────────────────────────────────────┘

toSecond

Returns the second component (0-59) of a date with time. Leap seconds are not considered.

Syntax

toSecond(value)

Alias: SECOND

Arguments

Returned value

  • The second in the minute (0 - 59) of the given date/time

Type: UInt8

Example

SELECT toSecond(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toSecond(toDateTime('2023-04-21 10:20:30'))─┐
│                                          30 │
└─────────────────────────────────────────────┘

toMillisecond

Returns the millisecond component (0-999) of a date with time.

Syntax

toMillisecond(value)

Arguments*

Alias: MILLISECOND

SELECT toMillisecond(toDateTime64('2023-04-21 10:20:30.456', 3))

Result:

┌──toMillisecond(toDateTime64('2023-04-21 10:20:30.456', 3))─┐
│                                                        456 │
└────────────────────────────────────────────────────────────┘

Returned value

  • The millisecond in the minute (0 - 59) of the given date/time

Type: UInt16

toUnixTimestamp

Converts a string, a date or a date with time to the Unix Timestamp in UInt32 representation.

If the function is called with a string, it accepts an optional timezone argument.

Syntax

toUnixTimestamp(date)
toUnixTimestamp(str, [timezone])

Returned value

  • Returns the unix timestamp.

Type: UInt32.

Example

SELECT
    '2017-11-05 08:07:47' AS dt_str,
    toUnixTimestamp(dt_str) AS from_str,
    toUnixTimestamp(dt_str, 'Asia/Tokyo') AS from_str_tokyo,
    toUnixTimestamp(toDateTime(dt_str)) AS from_datetime,
    toUnixTimestamp(toDateTime64(dt_str, 0)) AS from_datetime64,
    toUnixTimestamp(toDate(dt_str)) AS from_date,
    toUnixTimestamp(toDate32(dt_str)) AS from_date32
FORMAT Vertical;

Result:

Row 1:
──────
dt_str:          2017-11-05 08:07:47
from_str:        1509869267
from_str_tokyo:  1509836867
from_datetime:   1509869267
from_datetime64: 1509869267
from_date:       1509840000
from_date32:     1509840000

:::note The return type of toStartOf*, toLastDayOf*, toMonday, timeSlot functions described below is determined by the configuration parameter enable_extended_results_for_datetime_functions which is 0 by default.

Behavior for

  • enable_extended_results_for_datetime_functions = 0:
    • Functions toStartOfYear, toStartOfISOYear, toStartOfQuarter, toStartOfMonth, toStartOfWeek, toLastDayOfWeek, toLastDayOfMonth, toMonday return Date or DateTime.
    • Functions toStartOfDay, toStartOfHour, toStartOfFifteenMinutes, toStartOfTenMinutes, toStartOfFiveMinutes, toStartOfMinute, timeSlot return DateTime. Though these functions can take values of the extended types Date32 and DateTime64 as an argument, passing them a time outside the normal range (year 1970 to 2149 for Date / 2106 for DateTime) will produce wrong results.
  • enable_extended_results_for_datetime_functions = 1:
    • Functions toStartOfYear, toStartOfISOYear, toStartOfQuarter, toStartOfMonth, toStartOfWeek, toLastDayOfWeek, toLastDayOfMonth, toMonday return Date or DateTime if their argument is a Date or DateTime, and they return Date32 or DateTime64 if their argument is a Date32 or DateTime64.
    • Functions toStartOfDay, toStartOfHour, toStartOfFifteenMinutes, toStartOfTenMinutes, toStartOfFiveMinutes, toStartOfMinute, timeSlot return DateTime if their argument is a Date or DateTime, and they return DateTime64 if their argument is a Date32 or DateTime64. :::

toStartOfYear

Rounds down a date or date with time to the first day of the year. Returns the date as a Date object.

Syntax

toStartOfYear(value)

Arguments

Returned value

  • The first day of the year of the input date/time

Type: Date

Example

SELECT toStartOfYear(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toStartOfYear(toDateTime('2023-04-21 10:20:30'))─┐
│                                       2023-01-01 │
└──────────────────────────────────────────────────┘

toStartOfISOYear

Rounds down a date or date with time to the first day of the ISO year, which can be different than a "regular" year. (See https://en.wikipedia.org/wiki/ISO_week_date.)

Syntax

toStartOfISOYear(value)

Arguments

Returned value

  • The first day of the year of the input date/time

Type: Date

Example

SELECT toStartOfISOYear(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toStartOfISOYear(toDateTime('2023-04-21 10:20:30'))─┐
│                                          2023-01-02 │
└─────────────────────────────────────────────────────┘

toStartOfQuarter

Rounds down a date or date with time to the first day of the quarter. The first day of the quarter is either 1 January, 1 April, 1 July, or 1 October. Returns the date.

Syntax

toStartOfQuarter(value)

Arguments

Returned value

  • The first day of the quarter of the given date/time

Type: Date

Example

SELECT toStartOfQuarter(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toStartOfQuarter(toDateTime('2023-04-21 10:20:30'))─┐
│                                          2023-04-01 │
└─────────────────────────────────────────────────────┘

toStartOfMonth

Rounds down a date or date with time to the first day of the month. Returns the date.

Syntax

toStartOfMonth(value)

Arguments

Returned value

  • The first day of the month of the given date/time

Type: Date

Example

SELECT toStartOfMonth(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toStartOfMonth(toDateTime('2023-04-21 10:20:30'))─┐
│                                        2023-04-01 │
└───────────────────────────────────────────────────┘

:::note The behavior of parsing incorrect dates is implementation specific. ClickHouse may return zero date, throw an exception, or do “natural” overflow. :::

toLastDayOfMonth

Rounds a date or date with time to the last day of the month. Returns the date.

Syntax

toLastDayOfMonth(value)

Alias: LAST_DAY

Arguments

Returned value

  • The last day of the month of the given date/time

Type: Date

Example

SELECT toLastDayOfMonth(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toLastDayOfMonth(toDateTime('2023-04-21 10:20:30'))─┐
│                                          2023-04-30 │
└─────────────────────────────────────────────────────┘

toMonday

Rounds down a date or date with time to the nearest Monday. Returns the date.

Syntax

toMonday(value)

Arguments

Returned value

  • The date of the nearest Monday on or prior to the given date

Type: Date

Example

SELECT
    toMonday(toDateTime('2023-04-21 10:20:30')), /* a Friday */
    toMonday(toDate('2023-04-24')), /* already a Monday */

Result:

┌─toMonday(toDateTime('2023-04-21 10:20:30'))─┬─toMonday(toDate('2023-04-24'))─┐
│                                  2023-04-17 │                     2023-04-24 │
└─────────────────────────────────────────────┴────────────────────────────────┘

toStartOfWeek

Rounds a date or date with time down to the nearest Sunday or Monday. Returns the date. The mode argument works exactly like the mode argument in function toWeek(). If no mode is specified, it defaults to 0.

Syntax

toStartOfWeek(t[, mode[, timezone]])

Arguments

  • t - a Date, Date32, DateTime or DateTime64
  • mode - determines the first day of the week as described in the toWeek() function. Default: 0
  • timezone - Optional parameter, it behaves like any other conversion function

Returned value

  • The date of the nearest Sunday or Monday on or prior to the given date, depending on the mode

Type: Date

Example

SELECT
    toStartOfWeek(toDateTime('2023-04-21 10:20:30')), /* a Friday */
    toStartOfWeek(toDateTime('2023-04-21 10:20:30'), 1), /* a Friday */
    toStartOfWeek(toDate('2023-04-24')), /* a Monday */
    toStartOfWeek(toDate('2023-04-24'), 1) /* a Monday */
FORMAT Vertical

Result:

Row 1:
──────
toStartOfWeek(toDateTime('2023-04-21 10:20:30')):    2023-04-16
toStartOfWeek(toDateTime('2023-04-21 10:20:30'), 1): 2023-04-17
toStartOfWeek(toDate('2023-04-24')):                 2023-04-23
toStartOfWeek(toDate('2023-04-24'), 1):              2023-04-24

toLastDayOfWeek

Rounds a date or date with time up to the nearest Saturday or Sunday. Returns the date. The mode argument works exactly like the mode argument in function toWeek(). If no mode is specified, mode is assumed as 0.

Syntax

toLastDayOfWeek(t[, mode[, timezone]])

Arguments

  • t - a Date, Date32, DateTime or DateTime64
  • mode - determines the last day of the week as described in the toWeek() function
  • timezone - Optional parameter, it behaves like any other conversion function

Returned value

  • The date of the nearest Sunday or Monday on or after the given date, depending on the mode

Type: Date

Example

SELECT
    toLastDayOfWeek(toDateTime('2023-04-21 10:20:30')), /* a Friday */
    toLastDayOfWeek(toDateTime('2023-04-21 10:20:30'), 1), /* a Friday */
    toLastDayOfWeek(toDate('2023-04-22')), /* a Saturday */
    toLastDayOfWeek(toDate('2023-04-22'), 1) /* a Saturday */
FORMAT Vertical

Result:

Row 1:
──────
toLastDayOfWeek(toDateTime('2023-04-21 10:20:30')):    2023-04-22
toLastDayOfWeek(toDateTime('2023-04-21 10:20:30'), 1): 2023-04-23
toLastDayOfWeek(toDate('2023-04-22')):                 2023-04-22
toLastDayOfWeek(toDate('2023-04-22'), 1):              2023-04-23

toStartOfDay

Rounds down a date with time to the start of the day.

Syntax

toStartOfDay(value)

Arguments

Returned value

  • The start of the day of the given date/time

Type: DateTime

Example

SELECT toStartOfDay(toDateTime('2023-04-21 10:20:30'))

Result:

┌─toStartOfDay(toDateTime('2023-04-21 10:20:30'))─┐
│                             2023-04-21 00:00:00 │
└─────────────────────────────────────────────────┘

toStartOfHour

Rounds down a date with time to the start of the hour.

Syntax

toStartOfHour(value)

Arguments

Returned value

  • The start of the hour of the given date/time

Type: DateTime

Example

SELECT
    toStartOfHour(toDateTime('2023-04-21 10:20:30')),
    toStartOfHour(toDateTime64('2023-04-21', 6))

Result:

┌─toStartOfHour(toDateTime('2023-04-21 10:20:30'))─┬─toStartOfHour(toDateTime64('2023-04-21', 6))─┐
│                              2023-04-21 10:00:00 │                          2023-04-21 00:00:00 │
└──────────────────────────────────────────────────┴──────────────────────────────────────────────┘

toStartOfMinute

Rounds down a date with time to the start of the minute.

Syntax

toStartOfMinute(value)

Arguments

Returned value

  • The start of the minute of the given date/time

Type: DateTime

Example

SELECT
    toStartOfMinute(toDateTime('2023-04-21 10:20:30')),
    toStartOfMinute(toDateTime64('2023-04-21 10:20:30.5300', 8))
FORMAT Vertical

Result:

Row 1:
──────
toStartOfMinute(toDateTime('2023-04-21 10:20:30')):           2023-04-21 10:20:00
toStartOfMinute(toDateTime64('2023-04-21 10:20:30.5300', 8)): 2023-04-21 10:20:00

toStartOfSecond

Truncates sub-seconds.

Syntax

toStartOfSecond(value, [timezone])

Arguments

  • value — Date and time. DateTime64.
  • timezone — Timezone for the returned value (optional). If not specified, the function uses the timezone of the value parameter. String.

Returned value

  • Input value without sub-seconds.

Type: DateTime64.

Examples

Query without timezone:

WITH toDateTime64('2020-01-01 10:20:30.999', 3) AS dt64
SELECT toStartOfSecond(dt64);

Result:

┌───toStartOfSecond(dt64)─┐
│ 2020-01-01 10:20:30.000 │
└─────────────────────────┘

Query with timezone:

WITH toDateTime64('2020-01-01 10:20:30.999', 3) AS dt64
SELECT toStartOfSecond(dt64, 'Asia/Istanbul');

Result:

┌─toStartOfSecond(dt64, 'Asia/Istanbul')─┐
│                2020-01-01 13:20:30.000 │
└────────────────────────────────────────┘

See also

  • Timezone server configuration parameter.

toStartOfFiveMinutes

Rounds down a date with time to the start of the five-minute interval.

Syntax

toStartOfFiveMinutes(value)

Arguments

Returned value

  • The start of the five-minute interval of the given date/time

Type: DateTime

Example

SELECT
    toStartOfFiveMinutes(toDateTime('2023-04-21 10:17:00')),
    toStartOfFiveMinutes(toDateTime('2023-04-21 10:20:00')),
    toStartOfFiveMinutes(toDateTime('2023-04-21 10:23:00'))
FORMAT Vertical

Result:

Row 1:
──────
toStartOfFiveMinutes(toDateTime('2023-04-21 10:17:00')): 2023-04-21 10:15:00
toStartOfFiveMinutes(toDateTime('2023-04-21 10:20:00')): 2023-04-21 10:20:00
toStartOfFiveMinutes(toDateTime('2023-04-21 10:23:00')): 2023-04-21 10:20:00

toStartOfTenMinutes

Rounds down a date with time to the start of the ten-minute interval.

Syntax

toStartOfTenMinutes(value)

Arguments

Returned value

  • The start of the ten-minute interval of the given date/time

Type: DateTime

Example

SELECT
    toStartOfTenMinutes(toDateTime('2023-04-21 10:17:00')),
    toStartOfTenMinutes(toDateTime('2023-04-21 10:20:00')),
    toStartOfTenMinutes(toDateTime('2023-04-21 10:23:00'))
FORMAT Vertical

Result:

Row 1:
──────
toStartOfTenMinutes(toDateTime('2023-04-21 10:17:00')): 2023-04-21 10:10:00
toStartOfTenMinutes(toDateTime('2023-04-21 10:20:00')): 2023-04-21 10:20:00
toStartOfTenMinutes(toDateTime('2023-04-21 10:23:00')): 2023-04-21 10:20:00

toStartOfFifteenMinutes

Rounds down the date with time to the start of the fifteen-minute interval.

Syntax

toStartOfFifteenMinutes(value)

Arguments

Returned value

  • The start of the fifteen-minute interval of the given date/time

Type: DateTime

Example

SELECT
    toStartOfFifteenMinutes(toDateTime('2023-04-21 10:17:00')),
    toStartOfFifteenMinutes(toDateTime('2023-04-21 10:20:00')),
    toStartOfFifteenMinutes(toDateTime('2023-04-21 10:23:00'))
FORMAT Vertical

Result:

Row 1:
──────
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:17:00')): 2023-04-21 10:15:00
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:20:00')): 2023-04-21 10:15:00
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:23:00')): 2023-04-21 10:15:00

toStartOfInterval

This function generalizes other toStartOf*() functions. For example,

  • toStartOfInterval(t, INTERVAL 1 year) returns the same as toStartOfYear(t),
  • toStartOfInterval(t, INTERVAL 1 month) returns the same as toStartOfMonth(t),
  • toStartOfInterval(t, INTERVAL 1 day) returns the same as toStartOfDay(t),
  • toStartOfInterval(t, INTERVAL 15 minute) returns the same as toStartOfFifteenMinutes(t).

The calculation is performed relative to specific points in time:

Interval Start
year year 0
quarter 1900 Q1
month 1900 January
week 1970, 1st week (01-05)
day 1970-01-01
hour (*)
minute 1970-01-01 00:00:00
second 1970-01-01 00:00:00
millisecond 1970-01-01 00:00:00
microsecond 1970-01-01 00:00:00
nanosecond 1970-01-01 00:00:00

(*) hour intervals are special: the calculation is always performed relative to 00:00:00 (midnight) of the current day. As a result, only hour values between 1 and 23 are useful.

If unit week was specified, toStartOfInterval assumes by default that weeks start on Monday. You can change this behavior with setting first_day_of_week

See Also

toTime

Converts a date with time to a certain fixed date, while preserving the time.

toRelativeYearNum

Converts a date, or date with time, to the number of the year, starting from a certain fixed point in the past.

toRelativeQuarterNum

Converts a date, or date with time, to the number of the quarter, starting from a certain fixed point in the past.

toRelativeMonthNum

Converts a date, or date with time, to the number of the month, starting from a certain fixed point in the past.

toRelativeWeekNum

Converts a date, or date with time, to the number of the week, starting from a certain fixed point in the past.

toRelativeDayNum

Converts a date, or date with time, to the number of the day, starting from a certain fixed point in the past.

toRelativeHourNum

Converts a date, or date with time, to the number of the hour, starting from a certain fixed point in the past.

toRelativeMinuteNum

Converts a date, or date with time, to the number of the minute, starting from a certain fixed point in the past.

toRelativeSecondNum

Converts a date, or date with time, to the number of the second, starting from a certain fixed point in the past.

toISOYear

Converts a date, or date with time, to a UInt16 number containing the ISO Year number.

toISOWeek

Converts a date, or date with time, to a UInt8 number containing the ISO Week number.

toWeek

This function returns the week number for date or datetime. The two-argument form of toWeek() enables you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If the mode argument is omitted, the default mode is 0.

toISOWeek() is a compatibility function that is equivalent to toWeek(date,3).

The following table describes how the mode argument works.

Mode First day of week Range Week 1 is the first week …
0 Sunday 0-53 with a Sunday in this year
1 Monday 0-53 with 4 or more days this year
2 Sunday 1-53 with a Sunday in this year
3 Monday 1-53 with 4 or more days this year
4 Sunday 0-53 with 4 or more days this year
5 Monday 0-53 with a Monday in this year
6 Sunday 1-53 with 4 or more days this year
7 Monday 1-53 with a Monday in this year
8 Sunday 1-53 contains January 1
9 Monday 1-53 contains January 1

For mode values with a meaning of “with 4 or more days this year,” weeks are numbered according to ISO 8601:1988:

  • If the week containing January 1 has 4 or more days in the new year, it is week 1.

  • Otherwise, it is the last week of the previous year, and the next week is week 1.

For mode values with a meaning of “contains January 1”, the week contains January 1 is week 1. It does not matter how many days in the new year the week contained, even if it contained only one day. I.e. if the last week of December contains January 1 of the next year, it will be week 1 of the next year.

Syntax

toWeek(t[, mode[, time_zone]])

Alias: WEEK

Arguments

  • t – Date or DateTime.
  • mode – Optional parameter, Range of values is [0,9], default is 0.
  • Timezone – Optional parameter, it behaves like any other conversion function.

The first argument can also be specified as String in a format supported by parseDateTime64BestEffort(). Support for string arguments exists only for reasons of compatibility with MySQL which is expected by certain 3rd party tools. As string argument support may in future be made dependent on new MySQL-compatibility settings and because string parsing is generally slow, it is recommended to not use it.

Example

SELECT toDate('2016-12-27') AS date, toWeek(date) AS week0, toWeek(date,1) AS week1, toWeek(date,9) AS week9;

┌───────date─┬─week0─┬─week1─┬─week9─┐
│ 2016-12-27 │    52 │    52 │     1 │
└────────────┴───────┴───────┴───────┘

toYearWeek

Returns year and week for a date. The year in the result may be different from the year in the date argument for the first and the last week of the year.

The mode argument works like the mode argument to toWeek(). For the single-argument syntax, a mode value of 0 is used.

toISOYear() is a compatibility function that is equivalent to intDiv(toYearWeek(date,3),100).

:::warning The week number returned by toYearWeek() can be different from what the toWeek() returns. toWeek() always returns week number in the context of the given year, and in case toWeek() returns 0, toYearWeek() returns the value corresponding to the last week of previous year. See prev_yearWeek in example below. :::

Syntax

toYearWeek(t[, mode[, timezone]])

Alias: YEARWEEK

The first argument can also be specified as String in a format supported by parseDateTime64BestEffort(). Support for string arguments exists only for reasons of compatibility with MySQL which is expected by certain 3rd party tools. As string argument support may in future be made dependent on new MySQL-compatibility settings and because string parsing is generally slow, it is recommended to not use it.

Example

SELECT toDate('2016-12-27') AS date, toYearWeek(date) AS yearWeek0, toYearWeek(date,1) AS yearWeek1, toYearWeek(date,9) AS yearWeek9, toYearWeek(toDate('2022-01-01')) AS prev_yearWeek;

┌───────date─┬─yearWeek0─┬─yearWeek1─┬─yearWeek9─┬─prev_yearWeek─┐
│ 2016-12-27 │    201652 │    201652 │    201701 │        202152 │
└────────────┴───────────┴───────────┴───────────┴───────────────┘

toDaysSinceYearZero

Returns for a given date, the number of days passed since 1 January 0000 in the proleptic Gregorian calendar defined by ISO 8601. The calculation is the same as in MySQL's TO_DAYS() function.

Syntax

toDaysSinceYearZero(date[, time_zone])

Alias: TO_DAYS

Arguments

  • date — The date to calculate the number of days passed since year zero from. Date, Date32, DateTime or DateTime64.
  • time_zone — A String type const value or an expression represent the time zone. String types

Returned value

The number of days passed since date 0000-01-01.

Type: UInt32.

Example

SELECT toDaysSinceYearZero(toDate('2023-09-08'));

Result:

┌─toDaysSinceYearZero(toDate('2023-09-08')))─┐
│                                     713569 │
└────────────────────────────────────────────┘

See Also

fromDaysSinceYearZero

Returns for a given number of days passed since 1 January 0000 the corresponding date in the proleptic Gregorian calendar defined by ISO 8601. The calculation is the same as in MySQL's FROM_DAYS() function.

The result is undefined if it cannot be represented within the bounds of the Date type.

Syntax

fromDaysSinceYearZero(days)

Alias: FROM_DAYS

Arguments

  • days — The number of days passed since year zero.

Returned value

The date corresponding to the number of days passed since year zero.

Type: Date.

Example

SELECT fromDaysSinceYearZero(739136), fromDaysSinceYearZero(toDaysSinceYearZero(toDate('2023-09-08')));

Result:

┌─fromDaysSinceYearZero(739136)─┬─fromDaysSinceYearZero(toDaysSinceYearZero(toDate('2023-09-08')))─┐
│                    2023-09-08 │                                                       2023-09-08 │
└───────────────────────────────┴──────────────────────────────────────────────────────────────────┘

See Also

fromDaysSinceYearZero32

Like fromDaysSinceYearZero but returns a Date32.

age

Returns the unit component of the difference between startdate and enddate. The difference is calculated using a precision of 1 nanosecond. E.g. the difference between 2021-12-29 and 2022-01-01 is 3 days for day unit, 0 months for month unit, 0 years for year unit.

For an alternative to age, see function date_diff.

Syntax

age('unit', startdate, enddate, [timezone])

Arguments

  • unit — The type of interval for result. String. Possible values:

    • nanosecond, nanoseconds, ns
    • microsecond, microseconds, us, u
    • millisecond, milliseconds, ms
    • second, seconds, ss, s
    • minute, minutes, mi, n
    • hour, hours, hh, h
    • day, days, dd, d
    • week, weeks, wk, ww
    • month, months, mm, m
    • quarter, quarters, qq, q
    • year, years, yyyy, yy

  • startdate — The first time value to subtract (the subtrahend). Date, Date32, DateTime or DateTime64.

  • enddate — The second time value to subtract from (the minuend). Date, Date32, DateTime or DateTime64.

  • timezone — Timezone name (optional). If specified, it is applied to both startdate and enddate. If not specified, timezones of startdate and enddate are used. If they are not the same, the result is unspecified. String.

Returned value

Difference between enddate and startdate expressed in unit.

Type: Int.

Example

SELECT age('hour', toDateTime('2018-01-01 22:30:00'), toDateTime('2018-01-02 23:00:00'));

Result:

┌─age('hour', toDateTime('2018-01-01 22:30:00'), toDateTime('2018-01-02 23:00:00'))─┐
│                                                                                24 │
└───────────────────────────────────────────────────────────────────────────────────┘

SELECT
    toDate('2022-01-01') AS e,
    toDate('2021-12-29') AS s,
    age('day', s, e) AS day_age,
    age('month', s, e) AS month__age,
    age('year', s, e) AS year_age;

Result:

┌──────────e─┬──────────s─┬─day_age─┬─month__age─┬─year_age─┐
│ 2022-01-01 │ 2021-12-29 │       3 │          0 │        0 │
└────────────┴────────────┴─────────┴────────────┴──────────┘

date_diff

Returns the count of the specified unit boundaries crossed between the startdate and the enddate. The difference is calculated using relative units, e.g. the difference between 2021-12-29 and 2022-01-01 is 3 days for unit day (see toRelativeDayNum), 1 month for unit month (see toRelativeMonthNum) and 1 year for unit year (see toRelativeYearNum).

If unit week was specified, date_diff assumes that weeks start on Monday. Note that this behavior is different from that of function toWeek() in which weeks start by default on Sunday.

For an alternative to date_diff, see function age.

Syntax

date_diff('unit', startdate, enddate, [timezone])

Aliases: dateDiff, DATE_DIFF, timestampDiff, timestamp_diff, TIMESTAMP_DIFF.

Arguments

  • unit — The type of interval for result. String. Possible values:

    • nanosecond, nanoseconds, ns
    • microsecond, microseconds, us, u
    • millisecond, milliseconds, ms
    • second, seconds, ss, s
    • minute, minutes, mi, n
    • hour, hours, hh, h
    • day, days, dd, d
    • week, weeks, wk, ww
    • month, months, mm, m
    • quarter, quarters, qq, q
    • year, years, yyyy, yy

  • startdate — The first time value to subtract (the subtrahend). Date, Date32, DateTime or DateTime64.

  • enddate — The second time value to subtract from (the minuend). Date, Date32, DateTime or DateTime64.

  • timezone — Timezone name (optional). If specified, it is applied to both startdate and enddate. If not specified, timezones of startdate and enddate are used. If they are not the same, the result is unspecified. String.

Returned value

Difference between enddate and startdate expressed in unit.

Type: Int.

Example

SELECT dateDiff('hour', toDateTime('2018-01-01 22:00:00'), toDateTime('2018-01-02 23:00:00'));

Result:

┌─dateDiff('hour', toDateTime('2018-01-01 22:00:00'), toDateTime('2018-01-02 23:00:00'))─┐
│                                                                                     25 │
└────────────────────────────────────────────────────────────────────────────────────────┘

SELECT
    toDate('2022-01-01') AS e,
    toDate('2021-12-29') AS s,
    dateDiff('day', s, e) AS day_diff,
    dateDiff('month', s, e) AS month__diff,
    dateDiff('year', s, e) AS year_diff;

Result:

┌──────────e─┬──────────s─┬─day_diff─┬─month__diff─┬─year_diff─┐
│ 2022-01-01 │ 2021-12-29 │        3 │           1 │         1 │
└────────────┴────────────┴──────────┴─────────────┴───────────┘

date_trunc

Truncates date and time data to the specified part of date.

Syntax

date_trunc(unit, value[, timezone])

Alias: dateTrunc.

Arguments

  • unit — The type of interval to truncate the result. String Literal. Possible values:

    • nanosecond - Compatible only with DateTime64
    • microsecond - Compatible only with DateTime64
    • milisecond - Compatible only with DateTime64
    • second
    • minute
    • hour
    • day
    • week
    • month
    • quarter
    • year

    unit argument is case-insensitive.

  • value — Date and time. DateTime or DateTime64.

  • timezone — Timezone name for the returned value (optional). If not specified, the function uses the timezone of the value parameter. String.

Returned value

  • Value, truncated to the specified part of date.

Type: DateTime.

Example

Query without timezone:

SELECT now(), date_trunc('hour', now());

Result:

┌───────────────now()─┬─date_trunc('hour', now())─┐
│ 2020-09-28 10:40:45 │       2020-09-28 10:00:00 │
└─────────────────────┴───────────────────────────┘

Query with the specified timezone:

SELECT now(), date_trunc('hour', now(), 'Asia/Istanbul');

Result:

┌───────────────now()─┬─date_trunc('hour', now(), 'Asia/Istanbul')─┐
│ 2020-09-28 10:46:26 │                        2020-09-28 13:00:00 │
└─────────────────────┴────────────────────────────────────────────┘

See Also

date_add

Adds the time interval or date interval to the provided date or date with time.

If the addition results in a value outside the bounds of the data type, the result is undefined.

Syntax

date_add(unit, value, date)

Alternative syntax:

date_add(date, INTERVAL value unit)

Aliases: dateAdd, DATE_ADD.

Arguments

  • unit — The type of interval to add. Note: This is not a String and must therefore not be quoted. Possible values:

    • second
    • minute
    • hour
    • day
    • week
    • month
    • quarter
    • year

  • value — Value of interval to add. Int.

  • date — The date or date with time to which value is added. Date, Date32, DateTime or DateTime64.

Returned value

Date or date with time obtained by adding value, expressed in unit, to date.

Type: Date, Date32, DateTime or DateTime64.

Example

SELECT date_add(YEAR, 3, toDate('2018-01-01'));

Result:

┌─plus(toDate('2018-01-01'), toIntervalYear(3))─┐
│                                    2021-01-01 │
└───────────────────────────────────────────────┘

SELECT date_add(toDate('2018-01-01'), INTERVAL 3 YEAR);

Result:

┌─plus(toDate('2018-01-01'), toIntervalYear(3))─┐
│                                    2021-01-01 │
└───────────────────────────────────────────────┘

See Also

date_sub

Subtracts the time interval or date interval from the provided date or date with time.

If the subtraction results in a value outside the bounds of the data type, the result is undefined.

Syntax

date_sub(unit, value, date)

Alternative syntax:

date_sub(date, INTERVAL value unit)

Aliases: dateSub, DATE_SUB.

Arguments

  • unit — The type of interval to subtract. Note: This is not a String and must therefore not be quoted.

    Possible values:

    • second
    • minute
    • hour
    • day
    • week
    • month
    • quarter
    • year

  • value — Value of interval to subtract. Int.

  • date — The date or date with time from which value is subtracted. Date, Date32, DateTime or DateTime64.

Returned value

Date or date with time obtained by subtracting value, expressed in unit, from date.

Type: Date, Date32, DateTime or DateTime64.

Example

SELECT date_sub(YEAR, 3, toDate('2018-01-01'));

Result:

┌─minus(toDate('2018-01-01'), toIntervalYear(3))─┐
│                                     2015-01-01 │
└────────────────────────────────────────────────┘

SELECT date_sub(toDate('2018-01-01'), INTERVAL 3 YEAR);

Result:

┌─minus(toDate('2018-01-01'), toIntervalYear(3))─┐
│                                     2015-01-01 │
└────────────────────────────────────────────────┘

See Also

timestamp_add

Adds the specified time value with the provided date or date time value.

If the addition results in a value outside the bounds of the data type, the result is undefined.

Syntax

timestamp_add(date, INTERVAL value unit)

Aliases: timeStampAdd, TIMESTAMP_ADD.

Arguments

  • date — Date or date with time. Date, Date32, DateTime or DateTime64.

  • value — Value of interval to add. Int.

  • unit — The type of interval to add. String. Possible values:

    • second
    • minute
    • hour
    • day
    • week
    • month
    • quarter
    • year

Returned value

Date or date with time with the specified value expressed in unit added to date.

Type: Date, Date32, DateTime or DateTime64.

Example

select timestamp_add(toDate('2018-01-01'), INTERVAL 3 MONTH);

Result:

┌─plus(toDate('2018-01-01'), toIntervalMonth(3))─┐
│                                     2018-04-01 │
└────────────────────────────────────────────────┘

timestamp_sub

Subtracts the time interval from the provided date or date with time.

If the subtraction results in a value outside the bounds of the data type, the result is undefined.

Syntax

timestamp_sub(unit, value, date)

Aliases: timeStampSub, TIMESTAMP_SUB.

Arguments

  • unit — The type of interval to subtract. String. Possible values:

    • second
    • minute
    • hour
    • day
    • week
    • month
    • quarter
    • year

  • value — Value of interval to subtract. Int.

  • date — Date or date with time. Date, Date32, DateTime or DateTime64.

Returned value

Date or date with time obtained by subtracting value, expressed in unit, from date.

Type: Date, Date32, DateTime or DateTime64.

Example

select timestamp_sub(MONTH, 5, toDateTime('2018-12-18 01:02:03'));

Result:

┌─minus(toDateTime('2018-12-18 01:02:03'), toIntervalMonth(5))─┐
│                                          2018-07-18 01:02:03 │
└──────────────────────────────────────────────────────────────┘

addDate

Adds the time interval to the provided date, date with time or String-encoded date / date with time.

If the addition results in a value outside the bounds of the data type, the result is undefined.

Syntax

addDate(date, interval)

Arguments

Returned value

Date or date with time obtained by adding interval to date.

Type: Date, Date32, DateTime or DateTime64.

Example

SELECT addDate(toDate('2018-01-01'), INTERVAL 3 YEAR);

Result:

┌─addDate(toDate('2018-01-01'), toIntervalYear(3))─┐
│                                       2021-01-01 │
└──────────────────────────────────────────────────┘

Alias: ADDDATE

See Also

subDate

Subtracts the time interval from the provided date, date with time or String-encoded date / date with time.

If the subtraction results in a value outside the bounds of the data type, the result is undefined.

Syntax

subDate(date, interval)

Arguments

Returned value

Date or date with time obtained by subtracting interval from date.

Type: Date, Date32, DateTime or DateTime64.

Example

SELECT subDate(toDate('2018-01-01'), INTERVAL 3 YEAR);

Result:

┌─subDate(toDate('2018-01-01'), toIntervalYear(3))─┐
│                                       2015-01-01 │
└──────────────────────────────────────────────────┘

Alias: SUBDATE

See Also

now

Returns the current date and time at the moment of query analysis. The function is a constant expression.

Alias: current_timestamp.

Syntax

now([timezone])

Arguments

Returned value

  • Current date and time.

Type: DateTime.

Example

Query without timezone:

SELECT now();

Result:

┌───────────────now()─┐
│ 2020-10-17 07:42:09 │
└─────────────────────┘

Query with the specified timezone:

SELECT now('Asia/Istanbul');

Result:

┌─now('Asia/Istanbul')─┐
│  2020-10-17 10:42:23 │
└──────────────────────┘

now64

Returns the current date and time with sub-second precision at the moment of query analysis. The function is a constant expression.

Syntax

now64([scale], [timezone])

Arguments

  • scale - Tick size (precision): 10-precision seconds. Valid range: [ 0 : 9 ]. Typically, are used - 3 (default) (milliseconds), 6 (microseconds), 9 (nanoseconds).
  • timezone — Timezone name for the returned value (optional). String.

Returned value

  • Current date and time with sub-second precision.

Type: DateTime64.

Example

SELECT now64(), now64(9, 'Asia/Istanbul');

Result:

┌─────────────────now64()─┬─────now64(9, 'Asia/Istanbul')─┐
│ 2022-08-21 19:34:26.196 │ 2022-08-21 22:34:26.196542766 │
└─────────────────────────┴───────────────────────────────┘

nowInBlock

Returns the current date and time at the moment of processing of each block of data. In contrast to the function now, it is not a constant expression, and the returned value will be different in different blocks for long-running queries.

It makes sense to use this function to generate the current time in long-running INSERT SELECT queries.

Syntax

nowInBlock([timezone])

Arguments

Returned value

  • Current date and time at the moment of processing of each block of data.

Type: DateTime.

Example

SELECT
    now(),
    nowInBlock(),
    sleep(1)
FROM numbers(3)
SETTINGS max_block_size = 1
FORMAT PrettyCompactMonoBlock

Result:

┌───────────────now()─┬────────nowInBlock()─┬─sleep(1)─┐
│ 2022-08-21 19:41:19 │ 2022-08-21 19:41:19 │        0 │
│ 2022-08-21 19:41:19 │ 2022-08-21 19:41:20 │        0 │
│ 2022-08-21 19:41:19 │ 2022-08-21 19:41:21 │        0 │
└─────────────────────┴─────────────────────┴──────────┘

today

Returns the current date at moment of query analysis. It is the same as ‘toDate(now())’ and has aliases: curdate, current_date.

Syntax

today()

Arguments

  • None

Returned value

  • Current date

Type: DateTime.

Example

Query:

SELECT today() AS today, curdate() AS curdate, current_date() AS current_date FORMAT Pretty

Result:

Running the query above on the 3rd of March 2024 would have returned the following response:

┏━━━━━━━━━━━━┳━━━━━━━━━━━━┳━━━━━━━━━━━━━━┓
┃      today ┃    curdate ┃ current_date ┃
┡━━━━━━━━━━━━╇━━━━━━━━━━━━╇━━━━━━━━━━━━━━┩
│ 2024-03-03 │ 2024-03-03 │   2024-03-03 │
└────────────┴────────────┴──────────────┘

yesterday

Accepts zero arguments and returns yesterday’s date at one of the moments of query analysis. The same as ‘today() - 1’.

timeSlot

Rounds the time to the half hour.

toYYYYMM

Converts a date or date with time to a UInt32 number containing the year and month number (YYYY * 100 + MM). Accepts a second optional timezone argument. If provided, the timezone must be a string constant.

This function is the opposite of function YYYYMMDDToDate().

Example

SELECT
    toYYYYMM(now(), 'US/Eastern')

Result:

┌─toYYYYMM(now(), 'US/Eastern')─┐
│                        202303 │
└───────────────────────────────┘

toYYYYMMDD

Converts a date or date with time to a UInt32 number containing the year and month number (YYYY * 10000 + MM * 100 + DD). Accepts a second optional timezone argument. If provided, the timezone must be a string constant.

Example

SELECT toYYYYMMDD(now(), 'US/Eastern')

Result:

┌─toYYYYMMDD(now(), 'US/Eastern')─┐
│                        20230302 │
└─────────────────────────────────┘

toYYYYMMDDhhmmss

Converts a date or date with time to a UInt64 number containing the year and month number (YYYY * 10000000000 + MM * 100000000 + DD * 1000000 + hh * 10000 + mm * 100 + ss). Accepts a second optional timezone argument. If provided, the timezone must be a string constant.

Example

SELECT toYYYYMMDDhhmmss(now(), 'US/Eastern')

Result:

┌─toYYYYMMDDhhmmss(now(), 'US/Eastern')─┐
│                        20230302112209 │
└───────────────────────────────────────┘

YYYYMMDDToDate

Converts a number containing the year, month and day number to a Date.

This function is the opposite of function toYYYYMMDD().

The output is undefined if the input does not encode a valid Date value.

Syntax

YYYYMMDDToDate(yyyymmdd);

Arguments

Returned value

  • a date created from the arguments.

Type: Date.

Example

SELECT YYYYMMDDToDate(20230911);

Result:

┌─toYYYYMMDD(20230911)─┐
│           2023-09-11 │
└──────────────────────┘

YYYYMMDDToDate32

Like function YYYYMMDDToDate() but produces a Date32.

YYYYMMDDhhmmssToDateTime

Converts a number containing the year, month, day, hours, minute and second number to a DateTime.

The output is undefined if the input does not encode a valid DateTime value.

This function is the opposite of function toYYYYMMDDhhmmss().

Syntax

YYYYMMDDhhmmssToDateTime(yyyymmddhhmmss[, timezone]);

Arguments

  • yyyymmddhhmmss - A number representing the year, month and day. Integer, Float or Decimal.
  • timezone - Timezone for the returned value (optional).

Returned value

  • a date with time created from the arguments.

Type: DateTime.

Example

SELECT YYYYMMDDToDateTime(20230911131415);

Result:

┌──────YYYYMMDDhhmmssToDateTime(20230911131415)─┐
│                           2023-09-11 13:14:15 │
└───────────────────────────────────────────────┘

YYYYMMDDhhmmssToDateTime64

Like function YYYYMMDDhhmmssToDate() but produces a DateTime64.

Accepts an additional, optional precision parameter after the timezone parameter.

addYears, addQuarters, addMonths, addWeeks, addDays, addHours, addMinutes, addSeconds, addMilliseconds, addMicroseconds, addNanoseconds

These functions add units of the interval specified by the function name to a date, a date with time or a string-encoded date / date with time. A date or date with time is returned.

Example:

WITH
    toDate('2024-01-01') AS date,
    toDateTime('2024-01-01 00:00:00') AS date_time,
    '2024-01-01 00:00:00' AS date_time_string
SELECT
    addYears(date, 1) AS add_years_with_date,
    addYears(date_time, 1) AS add_years_with_date_time,
    addYears(date_time_string, 1) AS add_years_with_date_time_string

┌─add_years_with_date─┬─add_years_with_date_time─┬─add_years_with_date_time_string─┐
│          2025-01-01 │      2025-01-01 00:00:00 │         2025-01-01 00:00:00.000 │
└─────────────────────┴──────────────────────────┴─────────────────────────────────┘

subtractYears, subtractQuarters, subtractMonths, subtractWeeks, subtractDays, subtractHours, subtractMinutes, subtractSeconds, subtractMilliseconds, subtractMicroseconds, subtractNanoseconds

These functions subtract units of the interval specified by the function name from a date, a date with time or a string-encoded date / date with time. A date or date with time is returned.

Example:

WITH
    toDate('2024-01-01') AS date,
    toDateTime('2024-01-01 00:00:00') AS date_time,
    '2024-01-01 00:00:00' AS date_time_string
SELECT
    subtractYears(date, 1) AS subtract_years_with_date,
    subtractYears(date_time, 1) AS subtract_years_with_date_time,
    subtractYears(date_time_string, 1) AS subtract_years_with_date_time_string

┌─subtract_years_with_date─┬─subtract_years_with_date_time─┬─subtract_years_with_date_time_string─┐
│               2023-01-01 │           2023-01-01 00:00:00 │              2023-01-01 00:00:00.000 │
└──────────────────────────┴───────────────────────────────┴──────────────────────────────────────┘

timeSlots(StartTime, Duration,[, Size])

For a time interval starting at ‘StartTime’ and continuing for ‘Duration’ seconds, it returns an array of moments in time, consisting of points from this interval rounded down to the ‘Size’ in seconds. ‘Size’ is an optional parameter set to 1800 (30 minutes) by default. This is necessary, for example, when searching for pageviews in the corresponding session. Accepts DateTime and DateTime64 as ’StartTime’ argument. For DateTime, ’Duration’ and ’Size’ arguments must be UInt32. For ’DateTime64’ they must be Decimal64. Returns an array of DateTime/DateTime64 (return type matches the type of ’StartTime’). For DateTime64, the return value's scale can differ from the scale of ’StartTime’ --- the highest scale among all given arguments is taken.

Example:

SELECT timeSlots(toDateTime('2012-01-01 12:20:00'), toUInt32(600));
SELECT timeSlots(toDateTime('1980-12-12 21:01:02', 'UTC'), toUInt32(600), 299);
SELECT timeSlots(toDateTime64('1980-12-12 21:01:02.1234', 4, 'UTC'), toDecimal64(600.1, 1), toDecimal64(299, 0));

┌─timeSlots(toDateTime('2012-01-01 12:20:00'), toUInt32(600))─┐
│ ['2012-01-01 12:00:00','2012-01-01 12:30:00']               │
└─────────────────────────────────────────────────────────────┘
┌─timeSlots(toDateTime('1980-12-12 21:01:02', 'UTC'), toUInt32(600), 299)─┐
│ ['1980-12-12 20:56:13','1980-12-12 21:01:12','1980-12-12 21:06:11']     │
└─────────────────────────────────────────────────────────────────────────┘
┌─timeSlots(toDateTime64('1980-12-12 21:01:02.1234', 4, 'UTC'), toDecimal64(600.1, 1), toDecimal64(299, 0))─┐
│ ['1980-12-12 20:56:13.0000','1980-12-12 21:01:12.0000','1980-12-12 21:06:11.0000']                        │
└───────────────────────────────────────────────────────────────────────────────────────────────────────────┘

formatDateTime

Formats a Time according to the given Format string. Format is a constant expression, so you cannot have multiple formats for a single result column.

formatDateTime uses MySQL datetime format style, refer to https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_date-format.

The opposite operation of this function is parseDateTime.

Alias: DATE_FORMAT.

Syntax

formatDateTime(Time, Format[, Timezone])

Returned value(s)

Returns time and date values according to the determined format.

Replacement fields

Using replacement fields, you can define a pattern for the resulting string. “Example” column shows formatting result for 2018-01-02 22:33:44.

Placeholder Description Example
%a abbreviated weekday name (Mon-Sun) Mon
%b abbreviated month name (Jan-Dec) Jan
%c month as an integer number (01-12), see 'Note 3' below 01
%C year divided by 100 and truncated to integer (00-99) 20
%d day of the month, zero-padded (01-31) 02
%D Short MM/DD/YY date, equivalent to %m/%d/%y 01/02/18
%e day of the month, space-padded (1-31)   2
%f fractional second, see 'Note 1' below 1234560
%F short YYYY-MM-DD date, equivalent to %Y-%m-%d 2018-01-02
%g two-digit year format, aligned to ISO 8601, abbreviated from four-digit notation 18
%G four-digit year format for ISO week number, calculated from the week-based year defined by the ISO 8601 standard, normally useful only with %V 2018
%h hour in 12h format (01-12) 09
%H hour in 24h format (00-23) 22
%i minute (00-59) 33
%I hour in 12h format (01-12) 10
%j day of the year (001-366) 002
%k hour in 24h format (00-23), see 'Note 3' below 14
%l hour in 12h format (01-12), see 'Note 3' below 09
%m month as an integer number (01-12) 01
%M full month name (January-December), see 'Note 2' below January
%n new-line character (‘’)
%p AM or PM designation PM
%Q Quarter (1-4) 1
%r 12-hour HH:MM AM/PM time, equivalent to %h:%i %p 10:30 PM
%R 24-hour HH:MM time, equivalent to %H:%i 22:33
%s second (00-59) 44
%S second (00-59) 44
%t horizontal-tab character (’)
%T ISO 8601 time format (HH:MM:SS), equivalent to %H:%i:%S 22:33:44
%u ISO 8601 weekday as number with Monday as 1 (1-7) 2
%V ISO 8601 week number (01-53) 01
%w weekday as a integer number with Sunday as 0 (0-6) 2
%W full weekday name (Monday-Sunday) Monday
%y Year, last two digits (00-99) 18
%Y Year 2018
%z Time offset from UTC as +HHMM or -HHMM -0500
%% a % sign %

Note 1: In ClickHouse versions earlier than v23.4, %f prints a single zero (0) if the formatted value is a Date, Date32 or DateTime (which have no fractional seconds) or a DateTime64 with a precision of 0. The previous behavior can be restored using setting formatdatetime_f_prints_single_zero = 1.

Note 2: In ClickHouse versions earlier than v23.4, %M prints the minute (00-59) instead of the full month name (January-December). The previous behavior can be restored using setting formatdatetime_parsedatetime_m_is_month_name = 0.

Note 3: In ClickHouse versions earlier than v23.11, function parseDateTime() required leading zeros for formatters %c (month) and %l/%k (hour), e.g. 07. In later versions, the leading zero may be omitted, e.g. 7. The previous behavior can be restored using setting parsedatetime_parse_without_leading_zeros = 0. Note that function formatDateTime() by default still prints leading zeros for %c and %l/%k to not break existing use cases. This behavior can be changed by setting formatdatetime_format_without_leading_zeros = 1.

Example

SELECT formatDateTime(toDate('2010-01-04'), '%g')

Result:

┌─formatDateTime(toDate('2010-01-04'), '%g')─┐
│ 10                                         │
└────────────────────────────────────────────┘

SELECT formatDateTime(toDateTime64('2010-01-04 12:34:56.123456', 7), '%f')

Result:

┌─formatDateTime(toDateTime64('2010-01-04 12:34:56.123456', 7), '%f')─┐
│ 1234560                                                             │
└─────────────────────────────────────────────────────────────────────┘

Additionally, the formatDateTime function can take a third String argument containing the name of the time zone. Example: Asia/Istanbul. In this case, the time is formatted according to the specified time zone.

Example

SELECT
    now() AS ts,
    time_zone,
    formatDateTime(ts, '%T', time_zone) AS str_tz_time
FROM system.time_zones
WHERE time_zone LIKE 'Europe%'
LIMIT 10

┌──────────────────ts─┬─time_zone─────────┬─str_tz_time─┐
│ 2023-09-08 19:13:40 │ Europe/Amsterdam  │ 21:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Andorra    │ 21:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Astrakhan  │ 23:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Athens     │ 22:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Belfast    │ 20:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Belgrade   │ 21:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Berlin     │ 21:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Bratislava │ 21:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Brussels   │ 21:13:40    │
│ 2023-09-08 19:13:40 │ Europe/Bucharest  │ 22:13:40    │
└─────────────────────┴───────────────────┴─────────────┘

See Also

formatDateTimeInJodaSyntax

Similar to formatDateTime, except that it formats datetime in Joda style instead of MySQL style. Refer to https://joda-time.sourceforge.net/apidocs/org/joda/time/format/DateTimeFormat.html.

The opposite operation of this function is parseDateTimeInJodaSyntax.

Replacement fields

Using replacement fields, you can define a pattern for the resulting string.

Placeholder Description Presentation Examples
G era text AD
C century of era (>=0) number 20
Y year of era (>=0) year 1996
x weekyear (not supported yet) year 1996
w week of weekyear (not supported yet) number 27
e day of week number 2
E day of week text Tuesday; Tue
y year year 1996
D day of year number 189
M month of year month July; Jul; 07
d day of month number 10
a halfday of day text PM
K hour of halfday (0~11) number 0
h clockhour of halfday (1~12) number 12
H hour of day (0~23) number 0
k clockhour of day (1~24) number 24
m minute of hour number 30
s second of minute number 55
S fraction of second (not supported yet) number 978
z time zone (short name not supported yet) text Pacific Standard Time; PST
Z time zone offset/id (not supported yet) zone -0800; -08:00; America/Los_Angeles
' escape for text delimiter
'' single quote literal '

Example

SELECT formatDateTimeInJodaSyntax(toDateTime('2010-01-04 12:34:56'), 'yyyy-MM-dd HH:mm:ss')

Result:

┌─formatDateTimeInJodaSyntax(toDateTime('2010-01-04 12:34:56'), 'yyyy-MM-dd HH:mm:ss')─┐
│ 2010-01-04 12:34:56                                                                     │
└─────────────────────────────────────────────────────────────────────────────────────────┘

dateName

Returns specified part of date.

Syntax

dateName(date_part, date)

Arguments

  • date_part — Date part. Possible values: 'year', 'quarter', 'month', 'week', 'dayofyear', 'day', 'weekday', 'hour', 'minute', 'second'. String.
  • date — Date. Date, Date32, DateTime or DateTime64.
  • timezone — Timezone. Optional. String.

Returned value

  • The specified part of date.

Type: String

Example

WITH toDateTime('2021-04-14 11:22:33') AS date_value
SELECT
    dateName('year', date_value),
    dateName('month', date_value),
    dateName('day', date_value);

Result:

┌─dateName('year', date_value)─┬─dateName('month', date_value)─┬─dateName('day', date_value)─┐
│ 2021                         │ April                         │ 14                          │
└──────────────────────────────┴───────────────────────────────┴─────────────────────────────┘

monthName

Returns name of the month.

Syntax

monthName(date)

Arguments

Returned value

  • The name of the month.

Type: String

Example

WITH toDateTime('2021-04-14 11:22:33') AS date_value
SELECT monthName(date_value);

Result:

┌─monthName(date_value)─┐
│ April                 │
└───────────────────────┘

fromUnixTimestamp

This function converts a Unix timestamp to a calendar date and a time of a day.

It can be called in two ways:

When given a single argument of type Integer, it returns a value of type DateTime, i.e. behaves like toDateTime.

Alias: FROM_UNIXTIME.

Example:

SELECT fromUnixTimestamp(423543535);

Result:

┌─fromUnixTimestamp(423543535)─┐
│          1983-06-04 10:58:55 │
└──────────────────────────────┘

When given two or three arguments where the first argument is a value of type Integer, Date, Date32, DateTime or DateTime64, the second argument is a constant format string and the third argument is an optional constant time zone string, the function returns a value of type String, i.e. it behaves like formatDateTime. In this case, MySQL's datetime format style is used.

Example:

SELECT fromUnixTimestamp(1234334543, '%Y-%m-%d %R:%S') AS DateTime;

Result:

┌─DateTime────────────┐
│ 2009-02-11 14:42:23 │
└─────────────────────┘

See Also

fromUnixTimestampInJodaSyntax

Same as fromUnixTimestamp but when called in the second way (two or three arguments), the formatting is performed using Joda style instead of MySQL style.

Example:

SELECT fromUnixTimestampInJodaSyntax(1234334543, 'yyyy-MM-dd HH:mm:ss', 'UTC') AS DateTime;

Result:

┌─DateTime────────────┐
│ 2009-02-11 06:42:23 │
└─────────────────────┘

toModifiedJulianDay

Converts a Proleptic Gregorian calendar date in text form YYYY-MM-DD to a Modified Julian Day number in Int32. This function supports date from 0000-01-01 to 9999-12-31. It raises an exception if the argument cannot be parsed as a date, or the date is invalid.

Syntax

toModifiedJulianDay(date)

Arguments

Returned value

  • Modified Julian Day number.

Type: Int32.

Example

SELECT toModifiedJulianDay('2020-01-01');

Result:

┌─toModifiedJulianDay('2020-01-01')─┐
│                             58849 │
└───────────────────────────────────┘

toModifiedJulianDayOrNull

Similar to toModifiedJulianDay(), but instead of raising exceptions it returns NULL.

Syntax

toModifiedJulianDayOrNull(date)

Arguments

Returned value

  • Modified Julian Day number.

Type: Nullable(Int32).

Example

SELECT toModifiedJulianDayOrNull('2020-01-01');

Result:

┌─toModifiedJulianDayOrNull('2020-01-01')─┐
│                                   58849 │
└─────────────────────────────────────────┘

fromModifiedJulianDay

Converts a Modified Julian Day number to a Proleptic Gregorian calendar date in text form YYYY-MM-DD. This function supports day number from -678941 to 2973119 (which represent 0000-01-01 and 9999-12-31 respectively). It raises an exception if the day number is outside of the supported range.

Syntax

fromModifiedJulianDay(day)

Arguments

Returned value

  • Date in text form.

Type: String

Example

SELECT fromModifiedJulianDay(58849);

Result:

┌─fromModifiedJulianDay(58849)─┐
│ 2020-01-01                   │
└──────────────────────────────┘

fromModifiedJulianDayOrNull

Similar to fromModifiedJulianDayOrNull(), but instead of raising exceptions it returns NULL.

Syntax

fromModifiedJulianDayOrNull(day)

Arguments

Returned value

  • Date in text form.

Type: Nullable(String)

Example

SELECT fromModifiedJulianDayOrNull(58849);

Result:

┌─fromModifiedJulianDayOrNull(58849)─┐
│ 2020-01-01                         │
└────────────────────────────────────┘

toUTCTimestamp

Convert DateTime/DateTime64 type value from other time zone to UTC timezone timestamp

Syntax

toUTCTimestamp(time_val, time_zone)

Arguments

  • time_val — A DateTime/DateTime64 type const value or an expression . DateTime/DateTime64 types
  • time_zone — A String type const value or an expression represent the time zone. String types

Returned value

  • DateTime/DateTime64 in text form

Example

SELECT toUTCTimestamp(toDateTime('2023-03-16'), 'Asia/Shanghai');

Result:

┌─toUTCTimestamp(toDateTime('2023-03-16'),'Asia/Shanghai')┐
│                                     2023-03-15 16:00:00 │
└─────────────────────────────────────────────────────────┘

fromUTCTimestamp

Convert DateTime/DateTime64 type value from UTC timezone to other time zone timestamp

Syntax

fromUTCTimestamp(time_val, time_zone)

Arguments

  • time_val — A DateTime/DateTime64 type const value or an expression . DateTime/DateTime64 types
  • time_zone — A String type const value or an expression represent the time zone. String types

Returned value

  • DateTime/DateTime64 in text form

Example

SELECT fromUTCTimestamp(toDateTime64('2023-03-16 10:00:00', 3), 'Asia/Shanghai');

Result:

┌─fromUTCTimestamp(toDateTime64('2023-03-16 10:00:00',3),'Asia/Shanghai')─┐
│                                                 2023-03-16 18:00:00.000 │
└─────────────────────────────────────────────────────────────────────────┘

timeDiff

Returns the difference between two dates or dates with time values. The difference is calculated in units of seconds. It is same as dateDiff and was added only for MySQL support. dateDiff is preferred.

Syntax

timeDiff(first_datetime, second_datetime)

Arguments*

Returned value

The difference between two dates or dates with time values in seconds.

Example

Query:

timeDiff(toDateTime64('1927-01-01 00:00:00', 3), toDate32('1927-01-02'));

Result:

┌─timeDiff(toDateTime64('1927-01-01 00:00:00', 3), toDate32('1927-01-02'))─┐
│                                                                    86400 │
└──────────────────────────────────────────────────────────────────────────┘

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