John Lumby <johnlumby@hotmail.com> <DM6PR06MB55625C1A9319BC921F4FB4ACA3530@DM6PR06MB5562.namprd06.prod.outlook.com>
writes:
> What is not clear to me is how the "components" (aka "subfields") of an
> interval are defined.
The spec says that year,month,day,hour,minute,second are independent
fields. Postgres doesn't implement it quite that way: we treat the
basic fields as being months, days, and (micro)seconds, folding the
other values into those for storage. That's why "14 months" comes out
as "1 year 2 months", for example.
regards, tom lane