PostgreSQL JUSTIFY_HOURS() Function

Summary: in this tutorial, you will learn how to use the PostgreSQL JUSTIFY_HOURS() function to adjust 24-hour intervals as days.

Introduction to the PostgreSQL JUSTIFY_HOURS() function

The JUSTIFY_HOURS() function normalizes an interval by converting hours exceeding 24 to days.

Here’s the syntax of the JUSTIFY_HOURS() function:

JUSTIFY_HOURS ( value) → interval

In this syntax:

value is an interval value you want to justify.

The JUSTIFY_HOURS() function returns an adjusted interval with:

Hours exceeding 24 are converted to days.
The remaining hours are kept the same.
Minutes, seconds, and other units remain unchanged.

If the value is NULL, the function returns NULL.

PostgreSQL JUSTIFY_HOURS() function examples

Let’s take some examples of using the PostgreSQL JUSTIFY_HOURS() function.

1) Basic PostgreSQL JUSTIFY_HOURS() function example

The following statement uses the JUSTIFY_HOURS() function to adjust intervals that are multiples of 24 hours:

SELECT JUSTIFY_HOURS(INTERVAL '24 hours'),
       JUSTIFY_HOURS(INTERVAL '48 hours'),
       JUSTIFY_HOURS(INTERVAL '72 hours');

Output:

justify_hours | justify_hours | justify_hours
---------------+---------------+---------------
 1 day         | 2 days        | 3 days

2) Using JUSTIFY_HOURS() function with intervals that are not multiple of 24 hours

The following example uses the JUSTIFY_HOURS() function to adjust intervals that are not multiples of 24 hours:

SELECT JUSTIFY_HOURS(INTERVAL '25 hours'),
       JUSTIFY_HOURS(INTERVAL '50 hours'),
       JUSTIFY_HOURS(INTERVAL '70 hours');

Output:

justify_hours  |  justify_hours  |  justify_hours
----------------+-----------------+-----------------
 1 day 01:00:00 | 2 days 02:00:00 | 2 days 22:00:00

3) Using the JUSTIFY_HOURS() function with intervals that include hours

The following example uses the JUSTIFY_HOURS() function to adjust intervals that include hours, minutes, and seconds:

SELECT JUSTIFY_HOURS(INTERVAL '15 days 2 hours'),
       JUSTIFY_HOURS(INTERVAL '55 days 30 minutes'),
       JUSTIFY_HOURS(INTERVAL '75 days 45 seconds');

Output:

justify_days   |      justify_days      |      justify_days
------------------+------------------------+-------------------------
 15 days 02:00:00 | 1 mon 25 days 00:30:00 | 2 mons 15 days 00:00:45
(1 row)

Summary

Use the JUSTIFY_HOURS() function to adjust 24-hour intervals as days.