pg_extra_time

pg_extra_time : Some date time functions and operators that,

Overview

Packages

Source

pig build pkg pg_extra_time;		# build rpm/deb

Install

Make sure PGDG and PIGSTY repo available:

pig repo add pgsql -u   # add both repo and update cache

Install this extension with pig:

pig install pg_extra_time;		# install via package name, for the active PG version

pig install pg_extra_time -v 18;   # install for PG 18
pig install pg_extra_time -v 17;   # install for PG 17
pig install pg_extra_time -v 16;   # install for PG 16
pig install pg_extra_time -v 15;   # install for PG 15
pig install pg_extra_time -v 14;   # install for PG 14

Create this extension with:

CREATE EXTENSION pg_extra_time;

Usage

Sources: pg_extra_time upstream README, PGXN pg_extra_time, local metadata.

pg_extra_time provides small SQL functions and casts for date/time, interval, and range calculations that are awkward with PostgreSQL core functions alone.

CREATE EXTENSION pg_extra_time;

Convert to Seconds (float)

Use to_float(...) or explicit casts to float/double precision for timestamps, timestamp ranges, and intervals. Timestamp values are measured from the Unix epoch; ranges and intervals are measured by duration in seconds.

SELECT to_float('1970-01-01 00:00:00+0'::timestamptz);  -- 0.0
SELECT to_float('1970-01-01 00:00:00+0'::timestamp);    -- 0.0
SELECT to_float('1 day 1 sec'::interval);                -- 86401.0
SELECT to_float('[2024-06-06 05:58:00,2024-06-06 06:00:10]'::tstzrange);  -- 130.0
SELECT to_float('[2024-06-06 05:58:00,2024-06-06 06:00:10]'::tsrange);    -- 130.0

Cast syntax also works:

SELECT '1970-01-01 01:03:01+00'::timestamptz::float;    -- 3181.00
SELECT '1 day 1 sec 200 ms'::interval::float;            -- 86401.2
SELECT '[epoch,1970-01-01T01:03:01+00]'::tstzrange::float;  -- 3181.00

Convert to Days

Use days(...) when fractions matter and whole_days(...) when an integer number of complete days is needed.

SELECT days('[2024-06-06,2024-06-09)'::daterange);       -- 2
SELECT days('[2024-06-06,2024-06-08 06:00]'::tstzrange);  -- 3.25 (fractional days)
SELECT whole_days('[2024-06-06,2024-06-08 18:00]'::tstzrange);  -- 2
SELECT days('10 days 12 hours'::interval);                -- 10.5
SELECT whole_days('10 days 20 hours'::interval);          -- 10

whole_days(interval) handles negative intervals by applying the sign after flooring the absolute day count.

Count Date Parts

date_part_parts(part, subpart, timestamp with time zone, timezone) returns how many smaller date parts exist in a larger date part at a given timestamp and timezone. This helps with calculations where a day is not always 24 hours because of DST.

SELECT date_part_parts('month', 'days', '2024-02-12'::timestamptz, 'UTC');  -- 29
SELECT date_part_parts('year', 'days', '2024-08-23'::timestamptz, 'UTC');   -- 366

Build And Split Ranges

Use make_tstzrange or make_tsrange to build ranges from a timestamp and interval, including negative intervals.

SELECT make_tstzrange('2024-01-05 00:00+00'::timestamptz, '-4 days'::interval);
SELECT make_tsrange('2024-01-01 00:00'::timestamp, '4 days'::interval, '[)');

each_subperiod(tstzrange, interval, round_remainder integer DEFAULT 0) splits a timestamp range into interval-sized chunks. The remainder policy is: 1 rounds up to a full chunk, 0 keeps a partial final chunk, and -1 discards the remainder.

SELECT *
FROM each_subperiod(
  '[2023-01-01,2023-04-02)'::tstzrange,
  '1 month'::interval,
  0
);

Extract And Remainder Intervals

to_interval(tstzrange) extracts an interval from a timestamp range using month, day, and microsecond units. to_interval(tstzrange, interval[]) accepts explicit units in greatest-first order and rounds down by discarding the remainder.

SELECT to_interval('[2024-01-01,2024-01-05]'::tstzrange);  -- 4 days
SELECT to_interval(
  '[2024-01-01,2024-04-13 01:10]'::tstzrange,
  ARRAY['1 mon'::interval, '1 day'::interval, '1 hour'::interval]
);

Use % or modulo(...) when the remainder matters.

SELECT '10 seconds 100 milliseconds'::interval % '3 seconds'::interval;
SELECT '[2024-01-01,2024-01-10)'::tstzrange % '4 days'::interval;

Caveats

to_float(tstzrange) and to_float(tsrange) return positive or negative infinity for unbounded ranges and 0 for empty ranges. Integer casts are intentionally not provided; use whole_days(...) when you need integer days. Deprecated aliases such as extract_days(interval) and extract_interval(tstzrange, interval[]) remain for compatibility, but upstream recommends whole_days(...) and to_interval(...) instead.

Reference

Common public functions: