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Timestamp Functions

This section describes functions and operators for examining and manipulating TIMESTAMP values.

Timestamp Operators

The table below shows the available mathematical operators for TIMESTAMP types.

Operator Description Example Result
+ addition of an INTERVAL TIMESTAMP '1992-03-22 01:02:03' + INTERVAL 5 DAY 1992-03-27 01:02:03
- subtraction of TIMESTAMPs TIMESTAMP '1992-03-27' - TIMESTAMP '1992-03-22' 5 days
- subtraction of an INTERVAL TIMESTAMP '1992-03-27 01:02:03' - INTERVAL 5 DAY 1992-03-22 01:02:03

Adding to or subtracting from infinite values produces the same infinite value.

Timestamp Functions

The table below shows the available scalar functions for TIMESTAMP values.

Function Description Example Result
age(timestamp, timestamp) Subtract arguments, resulting in the time difference between the two timestamps age(TIMESTAMP '2001-04-10', TIMESTAMP '1992-09-20') 8 years 6 months 20 days
age(timestamp) Subtract from current_date age(TIMESTAMP '1992-09-20') 29 years 1 month 27 days 12:39:00.844
century(timestamp) Extracts the century of a timestamp century(TIMESTAMP '1992-03-22') 20
date_diff(part, startdate, enddate) The number of partition boundaries between the timestamps date_diff('hour', TIMESTAMP '1992-09-30 23:59:59', TIMESTAMP '1992-10-01 01:58:00') 2
date_part([part, ...], timestamp) Get the listed subfields as a struct. The list must be constant. date_part(['year', 'month', 'day'], TIMESTAMP '1992-09-20 20:38:40') {year: 1992, month: 9, day: 20}
date_part(part, timestamp) Get subfield (equivalent to extract) date_part('minute', TIMESTAMP '1992-09-20 20:38:40') 38
date_sub(part, startdate, enddate) The number of complete partitions between the timestamps date_sub('hour', TIMESTAMP '1992-09-30 23:59:59', TIMESTAMP '1992-10-01 01:58:00') 1
date_trunc(part, timestamp) Truncate to specified precision date_trunc('hour', TIMESTAMP '1992-09-20 20:38:40') 1992-09-20 20:00:00
datediff(part, startdate, enddate) Alias of date_diff. The number of partition boundaries between the timestamps datediff('hour', TIMESTAMP '1992-09-30 23:59:59', TIMESTAMP '1992-10-01 01:58:00') 2
datepart([part, ...], timestamp) Alias of date_part. Get the listed subfields as a struct. The list must be constant. datepart(['year', 'month', 'day'], TIMESTAMP '1992-09-20 20:38:40') {year: 1992, month: 9, day: 20}
datepart(part, timestamp) Alias of date_part. Get subfield (equivalent to extract) datepart('minute', TIMESTAMP '1992-09-20 20:38:40') 38
datesub(part, startdate, enddate) Alias of date_sub. The number of complete partitions between the timestamps datesub('hour', TIMESTAMP '1992-09-30 23:59:59', TIMESTAMP '1992-10-01 01:58:00') 1
datetrunc(part, timestamp) Alias of date_trunc. Truncate to specified precision datetrunc('hour', TIMESTAMP '1992-09-20 20:38:40') 1992-09-20 20:00:00
dayname(timestamp) The (English) name of the weekday dayname(TIMESTAMP '1992-03-22') Sunday
epoch_ms(ms) Converts ms since epoch to a timestamp epoch_ms(701222400000) 1992-03-22 00:00:00
epoch_ms(timestamp) Converts a timestamp to milliseconds since the epoch epoch_ms('2022-11-07 08:43:04.123456'::TIMESTAMP); 1667810584123
epoch_ms(timestamp) Return the total number of milliseconds since the epoch epoch_ms(timestamp '2021-08-03 11:59:44.123456') 1627991984123
epoch_ns(timestamp) Return the total number of nanoseconds since the epoch epoch_ns(timestamp '2021-08-03 11:59:44.123456') 1627991984123456000
epoch_us(timestamp) Return the total number of microseconds since the epoch epoch_ms(timestamp '2021-08-03 11:59:44.123456') 1627991984123456
epoch(timestamp) Converts a timestamp to seconds since the epoch epoch('2022-11-07 08:43:04'::TIMESTAMP); 1667810584
extract(field from timestamp) Get subfield from a timestamp extract('hour' FROM TIMESTAMP '1992-09-20 20:38:48') 20
greatest(timestamp, timestamp) The later of two timestamps greatest(TIMESTAMP '1992-09-20 20:38:48', TIMESTAMP '1992-03-22 01:02:03.1234') 1992-09-20 20:38:48
isfinite(timestamp) Returns true if the timestamp is finite, false otherwise isfinite(TIMESTAMP '1992-03-07') true
isinf(timestamp) Returns true if the timestamp is infinite, false otherwise isinf(TIMESTAMP '-infinity') true
last_day(timestamp) The last day of the month. last_day(TIMESTAMP '1992-03-22 01:02:03.1234') 1992-03-31
least(timestamp, timestamp) The earlier of two timestamps least(TIMESTAMP '1992-09-20 20:38:48', TIMESTAMP '1992-03-22 01:02:03.1234') 1992-03-22 01:02:03.1234
make_timestamp(bigint, bigint, bigint, bigint, bigint, double) The timestamp for the given parts make_timestamp(1992, 9, 20, 13, 34, 27.123456) 1992-09-20 13:34:27.123456
make_timestamp(microseconds) The timestamp for the given number of µs since the epoch make_timestamp(1667810584123456) 2022-11-07 08:43:04.123456
monthname(timestamp) The (English) name of the month. monthname(TIMESTAMP '1992-09-20') September
strftime(timestamp, format) Converts timestamp to string according to the format string strftime(timestamp '1992-01-01 20:38:40', '%a, %-d %B %Y - %I:%M:%S %p') Wed, 1 January 1992 - 08:38:40 PM
strptime(text, format-list) Converts string to timestamp applying the format strings in the list until one succeeds. Throws on failure. strptime('4/15/2023 10:56:00', ['%d/%m/%Y %H:%M:%S', '%m/%d/%Y %H:%M:%S']) 2023-04-15 10:56:00
strptime(text, format) Converts string to timestamp according to the format string. Throws on failure. strptime('Wed, 1 January 1992 - 08:38:40 PM', '%a, %-d %B %Y - %I:%M:%S %p') 1992-01-01 20:38:40
time_bucket(bucket_width, timestamp[, offset]) Truncate timestamp by the specified interval bucket_width. Buckets are offset by offset interval. time_bucket(INTERVAL '10 minutes', TIMESTAMP '1992-04-20 15:26:00-07', INTERVAL '5 minutes') 1992-04-20 15:25:00
time_bucket(bucket_width, timestamp[, origin]) Truncate timestamp by the specified interval bucket_width. Buckets are aligned relative to origin timestamp. origin defaults to 2000-01-03 00:00:00 for buckets that don’t include a month or year interval, and to 2000-01-01 00:00:00 for month and year buckets. time_bucket(INTERVAL '2 weeks', TIMESTAMP '1992-04-20 15:26:00', TIMESTAMP '1992-04-01 00:00:00') 1992-04-15 00:00:00
to_timestamp(double) Converts seconds since the epoch to a timestamp with time zone to_timestamp(1284352323.5) 2010-09-13 04:32:03.5+00
try_strptime(text, format-list) Converts string to timestamp applying the format strings in the list until one succeeds. Returns NULL on failure. try_strptime('4/15/2023 10:56:00', ['%d/%m/%Y %H:%M:%S', '%m/%d/%Y %H:%M:%S']) 2023-04-15 10:56:00
try_strptime(text, format) Converts string to timestamp according to the format string. Returns NULL on failure. try_strptime('Wed, 1 January 1992 - 08:38:40 PM', '%a, %-d %B %Y - %I:%M:%S %p') 1992-01-01 20:38:40

There are also dedicated extraction functions to get the subfields.

Functions applied to infinite dates will either return the same infinite dates (e.g, greatest) or NULL (e.g., date_part) depending on what “makes sense”. In general, if the function needs to examine the parts of the infinite date, the result will be NULL.

Timestamp Table Functions

The table below shows the available table functions for TIMESTAMP types.

Function Description Example
generate_series(timestamp, timestamp, interval) Generate a table of timestamps in the closed range, stepping by the interval generate_series(TIMESTAMP '2001-04-10', TIMESTAMP '2001-04-11', INTERVAL 30 MINUTE)
range(timestamp, timestamp, interval) Generate a table of timestamps in the half open range, stepping by the interval range(TIMESTAMP '2001-04-10', TIMESTAMP '2001-04-11', INTERVAL 30 MINUTE)

Infinite values are not allowed as table function bounds.

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Last modified: 2024-03-02