Function registerDataTypeTime

src/DataTypes/registerDataTypeDateTime.cpp:495–785

}

void registerDataTypeTime(DataTypeFactory & factory)
{
    factory.registerDataType("Time", createTime, DataTypeFactory::Case::Insensitive,
        Documentation{
            .description = R"DOCS_MD(
Data type `Time` represents a time with hour, minute, and second components.
It is independent of any calendar date and is suitable for values which do not need day, months and year components.

Syntax:

``` sql
Time
```

Text representation range: [-999:59:59, 999:59:59].

Resolution: 1 second.

## Implementation details {#implementation-details}

**Representation and Performance**.
Data type `Time` internally stores a signed 32-bit integer that encodes the seconds.
Values of type `Time` and `DateTime` have the same byte size and thus comparable performance.

**Normalization**.
When parsing strings to `Time`, the time components are normalized and not validated.
For example, `25:70:70` is interpreted as `26:11:10`.

**Negative values**.
Leading minus signs are supported and preserved.
Negative values typically arise from arithmetic operations on `Time` values.
For `Time` type, negative inputs are preserved for both text (e.g., `'-01:02:03'`) and numeric inputs (e.g., `-3723`).

**Saturation**.
The time-of-day component is capped to the range [-999:59:59, 999:59:59].
Values with hours beyond 999 (or below -999) are represented and round-tripped via text as `999:59:59` (or `-999:59:59`).

**Time zones**.
`Time` does not support time zones, i.e. `Time` value are interpreted without regional context.
Specifying a time zone for `Time` as a type parameter or during value creation throws an error.
Likewise, attempts to apply or change the time zone on `Time` columns are not supported and result in an error.
`Time` values are not silently reinterpreted under different time zones.

## Examples {#examples}

**1.** Creating a table with a `Time`-type column and inserting data into it:

``` sql
CREATE TABLE tab
(
    `event_id` UInt8,
    `time` Time
)
ENGINE = TinyLog;
```

``` sql
-- Parse Time