21.2:

```
milovidov-desktop :) SELECT CAST(1111111111.222 AS DateTime64(3))

SELECT cast(1111111111.222, 'DateTime64(3)')

Query id: d10c8623-5c74-4a38-b535-a99f6af4d28d

┌─cast(1111111111.222, 'DateTime64(3)')─┐
│               2005-03-18 04:58:31.222 │
└───────────────────────────────────────┘
```

master:

```
milovidov-desktop :) SELECT CAST(1111111111.222 AS DateTime64(3))

SELECT cast(1111111111.222, 'DateTime64(3)')

Query id: cb4af967-a4ae-4df5-89ba-234d68675f93

┌─cast(1111111111.222, 'DateTime64(3)')─┐
│               2005-03-18 04:58:31.000 │
└───────────────────────────────────────┘
```
}
    bool hasInformationAboutMonotonicity() const override
    {
        return Monotonic::has();
    }
    Monotonicity getMonotonicityForRange(const IDataType & type, const Field & left, const Field & right) const override
    {
        return Monotonic::get(type, left, right);
    }
private:
    mutable bool checked_return_type = false;
    mutable bool to_nullable = false;
    ColumnPtr executeInternal(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const
    {
        if (arguments.empty())
            throw Exception{"Function " + getName() + " expects at least 1 arguments",
               ErrorCodes::TOO_FEW_ARGUMENTS_FOR_FUNCTION};
        const IDataType * from_type = arguments[0].type.get();
        ColumnPtr result_column;
        auto call = [&](const auto & types, const auto & tag) -> bool
        {
            using Types = std::decay_t<decltype(types)>;
            using LeftDataType = typename Types::LeftType;
            using RightDataType = typename Types::RightType;
            using SpecialTag = std::decay_t<decltype(tag)>;
            if constexpr (IsDataTypeDecimal<RightDataType>)
            {
                if constexpr (std::is_same_v<RightDataType, DataTypeDateTime64>)
                {