TIME / TIMETZ

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The TIME data type stores the time of day in UTC.

The TIMETZ data type stores a time of day with a time zone offset from UTC.

Variants

TIME has two variants:

• TIME, which presents all TIME values in UTC.

• TIMETZ, which converts TIME values with a specified time zone offset from UTC.

  Ordering for TIMETZ is done in terms of epoch. Time zones with lesser values are ranked higher if times are equal. For example, '2:00-1' > '2:00+0' and '12:00-1' > '1:00+0'.

  Like Postgres, we implement the TIMETZ variant for SQL standards compliance. We also implement the TIMETZ variant for compatibility with ORMs, like Hibernate.

You can use the timezone() and AT TIME ZONE functions to convert a TIMETZ into a TIME at a specified timezone, or to convert a TIME into a TIMETZ at a specified timezone.

Aliases

In CockroachDB, the following are aliases:

Syntax

TIME

A constant value of type TIME can be expressed using an interpreted literal, or a string literal annotated with type TIME or coerced to type TIME. When it is unambiguous, a simple unannotated string literal can also be automatically interpreted as type TIME.

The string format for TIME is HH:MM:SS.SSSSSS. For example: TIME '05:40:00.000001'. The fractional portion is optional and is rounded to microseconds (i.e., six digits after the decimal) for compatibility with the PostgreSQL wire protocol.

TIMETZ

To express a TIMETZ value with a time zone offset from UTC, you can add an offset to a TIME value. For example, TIMETZ '10:10:10.555555-05:00' offsets from UTC by -5.

If no time zone is specified for a TIMETZ value, the timezone session variable is used. For example, if you set the timezone for a session using SET TIME ZONE -2, and you define the TIMETZ as TIMETZ '10:10:10.55', the value will be displayed with an offset of -2 from UTC.

TIMETZ is not affected by session-scoped offsets (unlike TIMESTAMPTZ). Time zone offsets only apply to values inserted after the offset has been set, and do not affect existing TIMETZ values, or TIMETZ values with a time zone offset specified.

Size

A TIME column supports values up to 8 bytes in width, but the total storage size is likely to be larger due to CockroachDB metadata.

A TIMETZ column supports values up to 12 bytes in width, but the total storage size is likely to be larger due to CockroachDB metadata.

Precision

CockroachDB supports precision levels from 0 (seconds) to 6 (microseconds) for TIME/TIMETZ values. Precision in time values specifies the number of fractional digits retained in the seconds field. For example, specifying a TIME value as TIME(3) truncates the time precision to milliseconds. By default, TIME/TIMETZ values have a precision of 6 (microseconds).

You can use an ALTER COLUMN ... SET DATA TYPE statement to change the precision level of a TIME-typed column. If there is already a non-default precision level specified for the column, the precision level can only be changed to an equal or greater precision level. For an example, see Create a table with a TIME-typed column, with precision.

Examples

Create a table with a TIME-typed column

> CREATE TABLE time (time_id INT PRIMARY KEY, time_val TIME);

> SHOW COLUMNS FROM time;

  column_name | data_type | is_nullable | column_default | generation_expression |  indices  | is_hidden
+-------------+-----------+-------------+----------------+-----------------------+-----------+-----------+
  time_id     | INT8      |    false    | NULL           |                       | {primary} |   false
  time_val    | TIME      |    true     | NULL           |                       | {}        |   false
(2 rows)

> INSERT INTO time VALUES (1, TIME '05:40:00'), (2, TIME '05:41:39');

> SELECT * FROM time;

  time_id |         time_val
+---------+---------------------------+
        1 | 0000-01-01 05:40:00+00:00
        2 | 0000-01-01 05:41:39+00:00
(2 rows)

Comparing TIME values:

> SELECT (SELECT time_val FROM time WHERE time_id = 1) < (SELECT time_val FROM time WHERE time_id = 2);

< (SELECT time_val FROM time WHERE time_id = 2);
  ?column?
+----------+
    true
(1 row)

Create a table with a TIME-typed column, with precision

> CREATE TABLE time (time_id INT PRIMARY KEY, time_val TIME(4));

> SHOW COLUMNS FROM time;

  column_name | data_type | is_nullable | column_default | generation_expression |  indices  | is_hidden
--------------+-----------+-------------+----------------+-----------------------+-----------+------------
  time_id     | INT8      |    false    | NULL           |                       | {primary} |   false
  time_val    | TIME(4)   |    true     | NULL           |                       | {}        |   false
(2 rows)

> INSERT INTO time VALUES (1, TIME '05:40:00.123456'), (2, TIME '05:41:39.12345');

> SELECT * FROM time;

  time_id |            time_val
----------+---------------------------------
        1 | 0000-01-01 05:40:00.1235+00:00
        2 | 0000-01-01 05:41:39.1235+00:00
(2 rows)

To change the precision level of a column, you can use an ALTER COLUMN ... SET DATA TYPE statement:

> ALTER TABLE time ALTER COLUMN time_val SET DATA TYPE TIME(5);

ALTER TABLE

> SHOW COLUMNS FROM time;

  column_name | data_type | is_nullable | column_default | generation_expression |  indices  | is_hidden
--------------+-----------+-------------+----------------+-----------------------+-----------+------------
  time_id     | INT8      |    false    | NULL           |                       | {primary} |   false
  time_val    | TIME(5)   |    true     | NULL           |                       | {}        |   false
(2 rows)

In this case, the time_val column, which is of type TIME(5), cannot be changed to a precision level below 5:

> ALTER TABLE time ALTER COLUMN time_val SET DATA TYPE TIME(3);

ERROR: unimplemented: type conversion from TIME(5) to TIME(3) requires overwriting existing values which is not yet implemented
SQLSTATE: 0A000

Supported casting & conversion

TIME/TIMETZ values can be cast to any of the following data types:

See also

• Data Types
• SQL Feature Support

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