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Time

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:

Time

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

Resolution: 1 second.

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​

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

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

-- Parse Time
-- - from string,
-- - from integer interpreted as number of seconds since 00:00:00.
INSERT INTO tab VALUES (1, '14:30:25'), (2, 52225);

SELECT * FROM tab ORDER BY event_id;

   ┌─event_id─┬──────time─┐
1. │        1 │ 14:30:25 │
2. │        2 │ 14:30:25 │
   └──────────┴───────────┘

2. Filtering on Time values

SELECT * FROM tab WHERE time = toTime('14:30:25')

   ┌─event_id─┬──────time─┐
1. │        1 │ 14:30:25 │
2. │        2 │ 14:30:25 │
   └──────────┴───────────┘

Time column values can be filtered using a string value in WHERE predicate. It will be converted to Time automatically:

SELECT * FROM tab WHERE time = '14:30:25'

   ┌─event_id─┬──────time─┐
1. │        1 │ 14:30:25 │
2. │        2 │ 14:30:25 │
   └──────────┴───────────┘

3. Inspecting the resulting type:

SELECT CAST('14:30:25' AS Time) AS column, toTypeName(column) AS type

   ┌────column─┬─type─┐
1. │ 14:30:25 │ Time │
   └───────────┴──────┘

See Also​