Return the date when the current transaction starts. This value does not change during the course of a transaction and does not reflect the individual start dates of statements within a transaction.

You can use the result of this function to calculate intervals between the current date and other datetime values in the database. For example:

premdb=# select CURRENT_DATE, matchday, CURRENT_DATE-matchday numdays 
FROM match WHERE seasonid=20 LIMIT 2;
    date    |      matchday       |  numdays  
 2016-05-20 | 2012-03-24 00:00:00 | 1518 days
 2016-05-20 | 2012-02-04 00:00:00 | 1567 days
(2 rows)