# Interval {#data-type-interval}

The family of data types representing time and date intervals. The resulting types of the [INTERVAL](../../query_language/operators.md#operator-interval) operator.

!!! warning "Warning"
    You can't use the `Interval` data types for storing values in tables.

Structure:

- Time interval as unsigned integer value.
- Type of an interval.

Supported interval types:

- `SECOND`
- `MINUTE`
- `HOUR`
- `DAY`
- `WEEK`
- `MONTH`
- `QUARTER`
- `YEAR`

For each interval type, there is the separated data type. For example, the `DAY` interval is expressed as the `IntervalDay` data type:

```sql
SELECT toTypeName(INTERVAL 4 DAY)
```
```text
┌─toTypeName(toIntervalDay(4))─┐
│ IntervalDay                  │
└──────────────────────────────┘
```

## Usage Remarks {#data-type-interval-usage-remarks}

You can use `Interval`-type values in arithmetical operations with [Date](../../data_types/date.md) and [DateTime](../../data_types/datetime.md)-type values. For example, you can add 4 days to the current time:

```sql
SELECT now() as current_date_time, current_date_time + INTERVAL 4 DAY
```
```text
┌───current_date_time─┬─plus(now(), toIntervalDay(4))─┐
│ 2019-10-23 10:58:45 │           2019-10-27 10:58:45 │
└─────────────────────┴───────────────────────────────┘
```

Intervals of different types can't be combined. You can't use intervals like `4 DAY 1 HOUR`, express intervals in the units that smaller or equal the the smallest unit of the interval. For example, `1 day and an hour` interval can be expressed as `25 HOUR` or `90000 SECOND`.

You can't perform arithmetical operations with the `Interval`-type values, but you can add intervals of different types consequently to some value. For example:

```sql
SELECT now() AS current_date_time, current_date_time + INTERVAL 4 DAY + INTERVAL 3 HOUR
```
```text
┌───current_date_time─┬─plus(plus(now(), toIntervalDay(4)), toIntervalHour(3))─┐
│ 2019-10-23 11:16:28 │                                    2019-10-27 14:16:28 │
└─────────────────────┴────────────────────────────────────────────────────────┘
```

The following query causes the exception:

```sql
select now() AS current_date_time, current_date_time + (INTERVAL 4 DAY + INTERVAL 3 HOUR)
```
```text
Received exception from server (version 19.14.1):
Code: 43. DB::Exception: Received from localhost:9000. DB::Exception: Wrong argument types for function plus: if one argument is Interval, then another must be Date or DateTime.. 
```

## See Also

- [INTERVAL](../../query_language/operators.md#operator-interval) operator
- [toInterval](../../query_language/functions/type_conversion_functions.md#function-tointerval) type convertion functions