How to convert an interval like “1 day 01:30:00” into “25:30:00”?

Question

I need to add some intervals and use the result in Excel.

Since

sum(time.endtime-time.starttime)

returns the interval as \"1 da

Answer 1

If you wanted postgres to handle the HH:MM:SS formatting for you, take the difference in epoch seconds and convert it to an interval scaled in seconds:

SELECT SUM(EXTRACT(EPOCH FROM time.endtime) - EXTRACT(EPOCH FROM time.starttime))
         * INTERVAL '1 SECOND' AS hhmmss