yugabyte=# SELECT EXTRACT(EPOCH FROM '1 Minute 30 Seconds'::INTERVAL) total_seconds;
total_seconds
---------------
90
(1 row)
yugabyte=# SELECT EXTRACT(EPOCH FROM '12 Years 12 Months 12 Days 12 Seconds'::INTERVAL) total_seconds;
total_seconds
---------------
411285612
(1 row)