In PostgreSQL, the current_timestamp() function returns the current date and time, including the time zone offset.

The timestamp returned is based on the start time of the current transaction.

In PostgreSQL, the localtimestamp() function returns the local date and time, without the time zone offset.

If you need the time zone offset, use current_timestamp() instead.

In PostgreSQL, the date_part() function retrieves subfields such as the year, month, hour, or minute, part from a date/time value.

It’s equivalent to the extract() function, although with a slightly different syntax.

In PostgreSQL, the extract() function retrieves subfields such as the year, month, hour, or minute, part from a date/time value.

It’s equivalent to the date_part() function, although with a slightly different syntax.

In PostgreSQL, the justify_interval() function adjusts an interval using justify_days and justify_hours. It allows you to use additional sign adjustments to adjust the interval.

In PostgreSQL, the justify_days() function allows you to adjust an interval value, so that 30-day time periods are represented as months.

For example, if you have an interval of say, 30 days, justify_days() will return it as 1 mon.

In PostgreSQL, the justify_hours() function allows you to adjust an interval value, so that 24-hour time periods are represented as days.

For example, if you have an interval of say, 24 hours justify_hours() will return it as 1 day.

In PostgreSQL, the isfinite() function tests for a finite date, timestamp or interval.

This can be useful, because Postgres supports infinite dates/timestamps. For example, you could have a timestamp of infinity or negative infinity, and this function allows you to test for that.