The TIME
data type stores the time of day in UTC.
New in v20.1: The TIMETZ
data type stores a time of day with a time zone offset from UTC.
Vectorized execution is currently not supported for this data type.
Variants
TIME
has two variants:
TIME
, which presents allTIME
values in UTC.TIMETZ
, which convertsTIME
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 theTIMETZ
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.
We recommend always using TIME
instead of TIMETZ
. Convert UTC values to the appropriate time zone on the client side.
Aliases
In CockroachDB, the following are aliases:
Alias | Long Version |
---|---|
TIME |
TIME WITHOUT TIME ZONE |
TIMETZ |
TIME WITH TIME ZONE |
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.
A date of 0000-01-01
is displayed for all TIME
/TIMETZ
values, but is not stored in the database. To print without a date, you can cast the type to a STRING
.
A time zone offset of +00:00
is also displayed for all TIME
and TIMESTAMP
values, but is not stored in the database.
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
New in v20.1: 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)
The SQL shell displays the date and time zone due to the Go SQL driver it uses. Other client drivers may behave similarly. In such cases, however, the date and time zone are not relevant and are not stored in the database.
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)
If a non-default precision level has already been specified, you cannot change the precision to a lower level.
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:
Type | Details |
---|---|
INTERVAL |
Converts to the span of time since midnight (00:00) |
STRING |
Converts to format 'HH:MM:SS.SSSSSS' (microsecond precision) |
CockroachDB displays TIME '24:00:00'
and TIMETZ '24:00:00'
as 0000-01-01 00:00:00
. To display the proper stored value (24:00:00
), you can cast the data type to a STRING
.