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.