-- difference in seconds between two dates
select extract(epoch from ('2020-03-30 09:55:56'::timestamp - '2020-03-30 08:54:55'::timestamp));
-- result : 3661select age('2010-04-01', '2012-03-05'),
date_part('year',age('2010-04-01', '2012-03-05')),
date_part('month',age('2010-04-01', '2012-03-05')),
date_part('day',age('2010-04-01', '2012-03-05')); -- Difference between Dec 30, 2011 08:54:55 and Dec 30, 2011 08:56:10 in minutes
SELECT (DATE_PART('day', '2011-12-30 08:56:10'::timestamp - '2011-12-30 08:54:55'::timestamp) * 24 * 60 +
DATE_PART('hour', '2011-12-30 08:56:10'::timestamp - '2011-12-30 08:54:55'::timestamp)) * 60 +
DATE_PART('minute', '2011-12-30 08:56:10'::timestamp - '2011-12-30 08:54:55'::timestamp);
-- Result: 1
-- Time only
SELECT DATE_PART('hour', '08:56:10'::time - '08:54:55'::time) * 60 +
DATE_PART('minute', '08:56:10'::time - '08:54:55'::time);
-- Result: 1