diff --git a/src/Functions/UTCTimestamp.cpp b/src/Functions/UTCTimestamp.cpp
new file mode 100644
index 00000000000..9b114754061
--- /dev/null
+++ b/src/Functions/UTCTimestamp.cpp
@@ -0,0 +1,117 @@
+#include <DataTypes/DataTypeDateTime.h>
+
+#include <Functions/IFunction.h>
+#include <Core/DecimalFunctions.h>
+#include <Functions/FunctionFactory.h>
+#include <Core/Field.h>
+
+#include <time.h>
+
+
+namespace DB
+{
+namespace ErrorCodes
+{
+    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
+}
+
+namespace
+{
+
+/// Get the UTC time. (It is a constant, it is evaluated once for the entire query.)
+class ExecutableFunctionUTCTimestamp : public IExecutableFunction
+{
+public:
+    explicit ExecutableFunctionUTCTimestamp(time_t time_) : time_value(time_) {}
+
+    String getName() const override { return "UTCTimestamp"; }
+
+    ColumnPtr executeImpl(const ColumnsWithTypeAndName &, const DataTypePtr &, size_t input_rows_count) const override
+    {
+        return DataTypeDateTime().createColumnConst(
+                input_rows_count,
+                static_cast<UInt64>(time_value));
+    }
+
+private:
+    time_t time_value;
+};
+
+class FunctionBaseUTCTimestamp : public IFunctionBase
+{
+public:
+    explicit FunctionBaseUTCTimestamp(time_t time_, DataTypes argument_types_, DataTypePtr return_type_)
+        : time_value(time_), argument_types(std::move(argument_types_)), return_type(std::move(return_type_)) {}
+
+    String getName() const override { return "UTCTimestamp"; }
+
+    const DataTypes & getArgumentTypes() const override
+    {
+        return argument_types;
+    }
+
+    const DataTypePtr & getResultType() const override
+    {
+        return return_type;
+    }
+
+    ExecutableFunctionPtr prepare(const ColumnsWithTypeAndName &) const override
+    {
+        return std::make_unique<ExecutableFunctionUTCTimestamp>(time_value);
+    }
+
+    bool isDeterministic() const override { return false; }
+    bool isDeterministicInScopeOfQuery() const override { return true; }
+    bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; }
+
+private:
+    time_t time_value;
+    DataTypes argument_types;
+    DataTypePtr return_type;
+};
+
+class UTCTimestampOverloadResolver : public IFunctionOverloadResolver
+{
+public:
+    static constexpr auto name = "UTCTimestamp";
+
+    String getName() const override { return name; }
+
+    bool isDeterministic() const override { return false; }
+
+    bool isVariadic() const override { return true; }
+
+    size_t getNumberOfArguments() const override { return 0; }
+    static FunctionOverloadResolverPtr create(ContextPtr) { return std::make_unique<UTCTimestampOverloadResolver>(); }
+
+    DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
+    {
+        if (arguments.size() > 0)
+        {
+            throw Exception("Arguments size of function " + getName() + " should be 0", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+        }
+
+        return std::make_shared<DataTypeDateTime>();
+    }
+
+    FunctionBasePtr buildImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &) const override
+    {
+        if (arguments.size() > 0)
+        {
+            throw Exception("Arguments size of function " + getName() + " should be 0", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+        }
+
+        return std::make_unique<FunctionBaseUTCTimestamp>(time(nullptr), DataTypes(), std::make_shared<DataTypeDateTime>("UTC"));
+    }
+};
+
+}
+
+/// UTC_timestamp for MySQL interface support
+REGISTER_FUNCTION(UTCTimestamp)
+{
+    factory.registerFunction<UTCTimestampOverloadResolver>({}, FunctionFactory::CaseInsensitive);
+    factory.registerAlias("UTC_timestamp", UTCTimestampOverloadResolver::name, FunctionFactory::CaseInsensitive);
+}
+
+}
diff --git a/src/Functions/timeDiff.cpp b/src/Functions/timeDiff.cpp
new file mode 100644
index 00000000000..9081351998f
--- /dev/null
+++ b/src/Functions/timeDiff.cpp
@@ -0,0 +1,228 @@
+#include <DataTypes/DataTypeDateTime.h>
+#include <DataTypes/DataTypeDateTime64.h>
+#include <DataTypes/DataTypesNumber.h>
+#include <Columns/ColumnString.h>
+#include <Columns/ColumnsNumber.h>
+#include <Columns/ColumnDecimal.h>
+
+#include <Functions/IFunction.h>
+#include <Functions/FunctionHelpers.h>
+#include <Functions/FunctionFactory.h>
+#include <Functions/extractTimeZoneFromFunctionArguments.h>
+#include <Functions/DateTimeTransforms.h>
+#include <Functions/TransformDateTime64.h>
+
+#include <IO/WriteHelpers.h>
+
+#include <base/find_symbols.h>
+
+#include <type_traits>
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
+    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
+    extern const int ILLEGAL_COLUMN;
+}
+
+namespace
+{
+
+/** TimeDiff(t1, t2)
+  * t1 and t2 can be Date or DateTime
+  */
+class FunctionTimeDiff : public IFunction
+{
+    using ColumnDateTime64 = ColumnDecimal<DateTime64>;
+public:
+    static constexpr auto name = "TimeDiff";
+    static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionTimeDiff>(); }
+
+    String getName() const override
+    {
+        return name;
+    }
+
+    bool isVariadic() const override { return true; }
+    bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return true; }
+    size_t getNumberOfArguments() const override { return 0; }
+
+    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
+    {
+        if (arguments.size() != 2)
+            throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
+                + toString(arguments.size()) + ", should be 2",
+                ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
+        if (!isDate(arguments[0]) && !isDateTime(arguments[0]) && !isDateTime64(arguments[1]))
+            throw Exception("First argument for function " + getName() + " must be Date or DateTime",
+                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+
+        if (!isDate(arguments[1]) && !isDateTime(arguments[1]) && !isDateTime64(arguments[2]))
+            throw Exception("Second argument for function " + getName() + " must be Date or DateTime",
+                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+
+        return std::make_shared<DataTypeInt64>();
+    }
+
+    bool useDefaultImplementationForConstants() const override { return true; }
+    ColumnNumbers getArgumentsThatAreAlwaysConstant() const override { return {}; }
+
+    ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
+    {
+        const IColumn & x = *arguments[0].column;
+        const IColumn & y = *arguments[1].column;
+
+        size_t rows = input_rows_count;
+        auto res = ColumnInt64::create(rows);
+
+        dispatchForColumns<ToRelativeSecondNumImpl>(x, y, DateLUT::instance(), DateLUT::instance(), res->getData());
+
+        return res;
+    }
+
+private:
+    template <typename Transform>
+    void dispatchForColumns(
+        const IColumn & x, const IColumn & y,
+        const DateLUTImpl & timezone_x, const DateLUTImpl & timezone_y,
+        ColumnInt64::Container & result) const
+    {
+        if (const auto * x_vec_16 = checkAndGetColumn<ColumnUInt16>(&x))
+            dispatchForSecondColumn<Transform>(*x_vec_16, y, timezone_x, timezone_y, result);
+        else if (const auto * x_vec_32 = checkAndGetColumn<ColumnUInt32>(&x))
+            dispatchForSecondColumn<Transform>(*x_vec_32, y, timezone_x, timezone_y, result);
+        else if (const auto * x_vec_64 = checkAndGetColumn<ColumnDateTime64>(&x))
+            dispatchForSecondColumn<Transform>(*x_vec_64, y, timezone_x, timezone_y, result);
+        else if (const auto * x_const_16 = checkAndGetColumnConst<ColumnUInt16>(&x))
+            dispatchConstForSecondColumn<Transform>(x_const_16->getValue<UInt16>(), y, timezone_x, timezone_y, result);
+        else if (const auto * x_const_32 = checkAndGetColumnConst<ColumnUInt32>(&x))
+            dispatchConstForSecondColumn<Transform>(x_const_32->getValue<UInt32>(), y, timezone_x, timezone_y, result);
+        else if (const auto * x_const_64 = checkAndGetColumnConst<ColumnDateTime64>(&x))
+            dispatchConstForSecondColumn<Transform>(x_const_64->getValue<DecimalField<DateTime64>>(), y, timezone_x, timezone_y, result);
+        else
+            throw Exception("Illegal column for first argument of function " + getName() + ", must be Date, DateTime or DateTime64", ErrorCodes::ILLEGAL_COLUMN);
+    }
+
+    template <typename Transform, typename LeftColumnType>
+    void dispatchForSecondColumn(
+        const LeftColumnType & x, const IColumn & y,
+        const DateLUTImpl & timezone_x, const DateLUTImpl & timezone_y,
+        ColumnInt64::Container & result) const
+    {
+        if (const auto * y_vec_16 = checkAndGetColumn<ColumnUInt16>(&y))
+            vectorVector<Transform>(x, *y_vec_16, timezone_x, timezone_y, result);
+        else if (const auto * y_vec_32 = checkAndGetColumn<ColumnUInt32>(&y))
+            vectorVector<Transform>(x, *y_vec_32, timezone_x, timezone_y, result);
+        else if (const auto * y_vec_64 = checkAndGetColumn<ColumnDateTime64>(&y))
+            vectorVector<Transform>(x, *y_vec_64, timezone_x, timezone_y, result);
+        else if (const auto * y_const_16 = checkAndGetColumnConst<ColumnUInt16>(&y))
+            vectorConstant<Transform>(x, y_const_16->getValue<UInt16>(), timezone_x, timezone_y, result);
+        else if (const auto * y_const_32 = checkAndGetColumnConst<ColumnUInt32>(&y))
+            vectorConstant<Transform>(x, y_const_32->getValue<UInt32>(), timezone_x, timezone_y, result);
+        else if (const auto * y_const_64 = checkAndGetColumnConst<ColumnDateTime64>(&y))
+            vectorConstant<Transform>(x, y_const_64->getValue<DecimalField<DateTime64>>(), timezone_x, timezone_y, result);
+        else
+            throw Exception("Illegal column for second argument of function " + getName() + ", must be Date or DateTime", ErrorCodes::ILLEGAL_COLUMN);
+    }
+
+    template <typename Transform, typename T1>
+    void dispatchConstForSecondColumn(
+        T1 x, const IColumn & y,
+        const DateLUTImpl & timezone_x, const DateLUTImpl & timezone_y,
+        ColumnInt64::Container & result) const
+    {
+        if (const auto * y_vec_16 = checkAndGetColumn<ColumnUInt16>(&y))
+            constantVector<Transform>(x, *y_vec_16, timezone_x, timezone_y, result);
+        else if (const auto * y_vec_32 = checkAndGetColumn<ColumnUInt32>(&y))
+            constantVector<Transform>(x, *y_vec_32, timezone_x, timezone_y, result);
+        else if (const auto * y_vec_64 = checkAndGetColumn<ColumnDateTime64>(&y))
+            constantVector<Transform>(x, *y_vec_64, timezone_x, timezone_y, result);
+        else
+            throw Exception("Illegal column for second argument of function " + getName() + ", must be Date or DateTime", ErrorCodes::ILLEGAL_COLUMN);
+    }
+
+    template <typename Transform, typename LeftColumnType, typename RightColumnType>
+    void vectorVector(
+        const LeftColumnType & x, const RightColumnType & y,
+        const DateLUTImpl & timezone_x, const DateLUTImpl & timezone_y,
+        ColumnInt64::Container & result) const
+    {
+        const auto & x_data = x.getData();
+        const auto & y_data = y.getData();
+
+        const auto transform_x = TransformDateTime64<Transform>(getScale(x));
+        const auto transform_y = TransformDateTime64<Transform>(getScale(y));
+        for (size_t i = 0, size = x.size(); i < size; ++i)
+                result[i] = calculate(transform_x, transform_y, x_data[i], y_data[i], timezone_x, timezone_y);
+    }
+
+    template <typename Transform, typename LeftColumnType, typename T2>
+    void vectorConstant(
+        const LeftColumnType & x, T2 y,
+        const DateLUTImpl & timezone_x, const DateLUTImpl & timezone_y,
+        ColumnInt64::Container & result) const
+    {
+        const auto & x_data = x.getData();
+        const auto transform_x = TransformDateTime64<Transform>(getScale(x));
+        const auto transform_y = TransformDateTime64<Transform>(getScale(y));
+        const auto y_value = stripDecimalFieldValue(y);
+
+        for (size_t i = 0, size = x.size(); i < size; ++i)
+            result[i] = calculate(transform_x, transform_y, x_data[i], y_value, timezone_x, timezone_y);
+    }
+
+    template <typename Transform, typename T1, typename RightColumnType>
+    void constantVector(
+        T1 x, const RightColumnType & y,
+        const DateLUTImpl & timezone_x, const DateLUTImpl & timezone_y,
+        ColumnInt64::Container & result) const
+    {
+        const auto & y_data = y.getData();
+        const auto transform_x = TransformDateTime64<Transform>(getScale(x));
+        const auto transform_y = TransformDateTime64<Transform>(getScale(y));
+        const auto x_value = stripDecimalFieldValue(x);
+
+        for (size_t i = 0, size = y.size(); i < size; ++i)
+            result[i] = calculate(transform_x, transform_y, x_value, y_data[i], timezone_x, timezone_y);
+    }
+
+    template <typename TransformX, typename TransformY, typename T1, typename T2>
+    Int64 calculate(const TransformX & transform_x, const TransformY & transform_y, T1 x, T2 y, const DateLUTImpl & timezone_x, const DateLUTImpl & timezone_y) const
+    {
+        return static_cast<Int64>(transform_y.execute(y, timezone_y))
+             - static_cast<Int64>(transform_x.execute(x, timezone_x));
+    }
+
+    template <typename T>
+    static UInt32 getScale(const T & v)
+    {
+        if constexpr (std::is_same_v<T, ColumnDateTime64>)
+            return v.getScale();
+        else if constexpr (std::is_same_v<T, DecimalField<DateTime64>>)
+            return v.getScale();
+
+        return 0;
+    }
+    template <typename T>
+    static auto stripDecimalFieldValue(T && v)
+    {
+        if constexpr (std::is_same_v<std::decay_t<T>, DecimalField<DateTime64>>)
+            return v.getValue();
+        else
+            return v;
+    }
+};
+
+}
+
+REGISTER_FUNCTION(TimeDiff)
+{
+    factory.registerFunction<FunctionTimeDiff>({}, FunctionFactory::CaseInsensitive);
+}
+
+}