Functions for date and time

Functions for date and time are functions for working with data of types DATE, TIME, TIMESTAMP and TIMESTAMPTZ.

current_time()

Description

Returns the current time as a value of type TIME.
Usage

current_time or current_time()
Aliases

get_current_time()
See example 
SELECT
    current_time       AS cur_time_1,
    current_time()     AS cur_time_2,
    get_current_time() AS cur_time_3;
+-----------------+-----------------+-----------------+
|    cur_time_1   |    cur_time_2   |    cur_time_3   |
+-----------------+-----------------+-----------------+
| 10:33:24.016000 | 10:33:24.016000 | 10:33:24.016000 |
+-----------------+-----------------+-----------------+

now()

Description

Returns the current time as a value of type TIMESTAMPTZ
Usage

now()
See example 
SELECT
    now() AS cur_time;
+----------------------------------+
| cur_time                         |
+----------------------------------+
| 2025-08-26 13:38:58.461000+00:00 |
+----------------------------------+

datepart()

Description

Returns the specified part of the date or time value as a value of type BIGINT.
Usage

datepart('<part>', (TIME | DATE | ...) <date_time>).
Aliases

date_part()

Arguments can be values of types: TIME, DATE, TIMESTAMP, or TIMESTAMPTZ.

Parts can be specified using the following literals

  • century

  • day

  • decade

  • hour

  • microseconds

  • millennium

  • milliseconds

  • minute

  • month

  • quarter

  • second

  • year

See examples 
SELECT
    datepart('milliseconds', TIMESTAMP '2025-02-25 00:00:00.1') AS milliseconds,
    datepart('hour',         TIME '2025-02-25 00:00:00')        AS hour,
    datepart('millennium',   DATE '2025-02-25')                 AS millennium;
+--------------+------+------------+
| milliseconds | hour | millennium |
+--------------+------+------------+
| 100          | 0    | 3          |
+--------------+------+------------+

date_diff()

Description

Returns the number of time units between two points in time as a value of type BIGINT.
Usage

date_diff('<part>', start, end)

Arguments can be values of type: TIME, DATE, TIMESTAMP, or TIMESTAMPTZ.

Units can be specified using the following literals

  • century

  • day

  • decade

  • hour

  • microseconds

  • millennium

  • milliseconds

  • minute

  • month

  • quarter

  • second

  • year

See examples 
SELECT
    date_diff('second', TIME '01:02:03', TIME '03:02:01') AS diff_in_seconds,
    date_diff('minute', TIME '01:02:03', TIME '03:02:01') AS diff_in_minutes,
    date_diff('hour',   TIME '01:02:03', TIME '03:02:01') AS diff_in_hours,
    date_diff('day',    TIMESTAMP '2025-02-25 01:02:03', TIMESTAMP '2025-02-26 03:02:01') AS diff_in_days,
    date_diff('day',    TIMESTAMP '2025-02-26 01:02:03', TIMESTAMP '2025-02-25 03:02:01') AS diff_in_days,
    date_diff('day',    DATE '2024-02-27', DATE '2025-02-27') AS diff_in_days;
+-----------------+-----------------+---------------+--------------+--------------+--------------+
| diff_in_seconds | diff_in_minutes | diff_in_hours | diff_in_days | diff_in_days | diff_in_days |
+-----------------+-----------------+---------------+--------------+--------------+--------------+
| 7198            | 120             | 2             | 1            | -1           | 366          |
+-----------------+-----------------+---------------+--------------+--------------+--------------+

date_trunc()

Description

Reduces a moment in time to the specified precision.
Usage

date_trunc('<part>', <time_stamp>)

Reduces the TIMESTAMP time moment to the specified precision unit and returns the initial time moment for that unit as a value of type TIMESTAMP or DATE.

Some usage examples are described in this script.

Units can be specified using the following literals

  • century

  • day

  • decade

  • hour

  • microseconds

  • millennium

  • milliseconds

  • minute

  • month

  • quarter

  • second

  • year

See examples 
SELECT
    date_trunc('minute',    TIMESTAMP '2025-02-25 01:02:03') AS minute,
    date_trunc('hour',      TIMESTAMP '2025-02-25 01:02:03') AS hour,
    date_trunc('day',       TIMESTAMP '2025-02-25 01:02:03') AS day,
    date_trunc('month',     TIMESTAMP '2025-02-25 01:02:03') AS month,
    date_trunc('quarter',   TIMESTAMP '2025-02-25 01:02:03') AS quarter,
    date_trunc('year',      TIMESTAMP '2025-02-25 01:02:03') AS year;
+---------------------+---------------------+------------+------------+------------+------------+
| minute              | hour                | day        | month      | quarter    | year       |
+---------------------+---------------------+------------+------------+------------+------------+
| 2025-02-25 01:02:00 | 2025-02-25 01:00:00 | 2025-02-25 | 2025-02-01 | 2025-01-01 | 2025-01-01 |
+---------------------+---------------------+------------+------------+------------+------------+

strptime()

Description

Converts text to a point in time using the specified format.
Usage

strptime(<string>, <format>)

Converts text to the point in time TIMESTAMP using the specified format. If the conversion fails, it generates an error.

Some usage examples are described in this script.

Format can be specified using the following expressions
Expression Description Example

%a

Abbreviated weekday name.

Sun, Mon, …

%A

Full weekday name.

Sunday, Monday, …

%b

Abbreviated month name.

Jan, Feb, …, Dec

%B

Full month name.

January, February, …

%c

ISO date and time representation

1992-03-02 10:30:20

%d

Day of the month as a zero-padded decimal.

01, 02, …, 31

%-d

Day of the month as a decimal number.

1, 2, …, 30

%f

Microsecond as a decimal number, zero-padded on the left.

000000 - 999999

%g

Millisecond as a decimal number, zero-padded on the left.

000 - 999

%G

ISO 8601 year with century representing the year that contains the greater part of the ISO week (see %V).

0001, 0002, …, 2013, 2014, …, 9998, 9999

%H

Hour (24-hour clock) as a zero-padded decimal number.

00, 01, …, 23

%-H

Hour (24-hour clock) as a decimal number.

0, 1, …, 23

%I

Hour (12-hour clock) as a zero-padded decimal number.

01, 02, …, 12

%-I

Hour (12-hour clock) as a decimal number.

1, 2, … 12

%j

Day of the year as a zero-padded decimal number.

001, 002, …, 366

%-j

Day of the year as a decimal number.

1, 2, …, 366

%m

Month as a zero-padded decimal number.

01, 02, …, 12

%-m

Month as a decimal number.

1, 2, …, 12

%M

Minute as a zero-padded decimal number.

00, 01, …, 59

%-M

Minute as a decimal number.

0, 1, …, 59

%n

Nanosecond as a decimal number, zero-padded on the left.

000000000 - 999999999

%p

Locale’s AM or PM.

AM, PM

%S

Second as a zero-padded decimal number.

00, 01, …, 59

%-S

Second as a decimal number.

0, 1, …, 59

%u

ISO 8601 weekday as a decimal number where 1 is Monday.

1, 2, …, 7

%U

Week number of the year. Week 01 starts on the first Sunday of the year, so there can be week 00. Note that this is not compliant with the week date standard in ISO-8601.

00, 01, …, 53

%V

ISO 8601 week as a decimal number with Monday as the first day of the week. Week 01 is the week containing Jan 4. Note that %V is incompatible with year directive %Y. Use the ISO year %G instead.

01, …, 53

%w

Weekday as a decimal number.

0, 1, …, 6

%W

Week number of the year. Week 01 starts on the first Monday of the year, so there can be week 00. Note that this is not compliant with the week date standard in ISO-8601.

00, 01, …, 53

%x

ISO date representation

1992-03-02

%X

ISO time representation

10:30:20

%y

Year without century as a zero-padded decimal number.

00, 01, …, 99

%-y

Year without century as a decimal number.

0, 1, …, 99

%Y

Year with century as a decimal number.

2013, 2019 etc.

%z

Time offset from UTC in the form ±HH:MM, ±HHMM, or ±HH.

-0700

%Z

Time zone name.

Europe/Amsterdam

%%

A literal % character.

%
See examples 
SELECT
    strptime('Feb 25, 2025, 01:02:03 AM', '%b %d, %Y, %H:%M:%S %p') AS timestamp_1,
    strptime('2025-02-25, 01:02:03',      '%x, %X')                 AS timestamp_2,
    strptime('01:02, 01.02.99',           '%H:%M, %d.%m.%y')        AS timestamp_3,
    strptime('01:02%PM--01.02.99',        '%H:%M%%%p--%d.%m.%y')    AS timestamp_4,
    strptime('1:1, 1.1.1',                '%-H:%-M, %-d.%-m.%-y')   AS timestamp_5,
    strptime('1',                         '%Y')                     AS timestamp_6;
+---------------------+---------------------+---------------------+---------------------+---------------------+---------------------+
| timestamp_1         | timestamp_2         | timestamp_3         | timestamp_4         | timestamp_5         | timestamp_6         |
+---------------------+---------------------+---------------------+---------------------+---------------------+---------------------+
| 2025-02-25 01:02:03 | 2025-02-25 01:02:03 | 1999-02-01 01:02:00 | 1999-02-01 13:02:00 | 2001-01-01 01:01:00 | 0001-01-01 00:00:00 |
+---------------------+---------------------+---------------------+---------------------+---------------------+---------------------+

Operator +

Description

Adds the right argument to the left argument.
Usage

<num> + <num> [+ ...] or TIME + INTERVAL [+ ...].

If used with types for for date and time, adds the interval to the time value. Returns a value of type TIME.

See also add().

See examples 
SELECT
    3 + 2      AS result_1,
    3 + 2 + -1 AS result_2,
    1.1 + 1.9  AS result_3;
+----------+----------+----------+
| result_1 | result_2 | result_3 |
+----------+----------+----------+
| 5        | 4        | 3.0      |
+----------+----------+----------+
SELECT
    TIME '12:11:10'     + INTERVAL 3 hours AS result_time_1,
    INTERVAL '12:11:10' + TIME '1:1:1'     AS result_time_2;
+---------------+---------------+
| result_time_1 | result_time_2 |
+---------------+---------------+
| 15:11:10      | 13:12:11      |
+---------------+---------------+

Operator -

Description

Subtracts the right argument from the left argument.
Usage

<num> - <num> [-...] or TIME - INTERVAL [-...].

If used with types for for date and time, subtracts the interval from the time value. Returns a value of type TIME.

See also subtract().

See examples 
SELECT
    3 - 2      AS result_1,
    3 - 2 - +1 AS result_2,
    1.2 - 0.2  AS result_3;
+----------+----------+----------+
| result_1 | result_2 | result_3 |
+----------+----------+----------+
| 1        | 0        | 1.0      |
+----------+----------+----------+
SELECT
    TIME '12:11:10' - INTERVAL 3 HOUR AS result_time_1,
    TIME '12:11:10' - INTERVAL 3 HOUR - INTERVAL 1 HOUR AS result_time_2;
+---------------+---------------+
| result_time_1 | result_time_2 |
+---------------+---------------+
| 09:11:10      | 08:11:10      |
+---------------+---------------+