Gerhard, Check out:
http://www.postgresql.org/docs/8.3/interactive/functions-datetime.html In particular, look at 'age()' or 'justify_days()', but I think age() is the one you want. SELECT age('2008-02-01'::timestamp, '2008-01-01'::timestamp) AS "1 month" Produces: "1 mon" SELECT justify_days('2008-02-01'::timestamp - '2008-01-01'::timestamp) AS "1 month" Produces "1 mon 1 day" One thing to be aware of is the different behaviors in these functions. age() uses the actual number of days in the month when representing the time, where justify_days() always assumes 30 days. In your example, January has 31 days, not 30, which is why the difference of '1 day' in the output. It's a little more obvious in this example, where both queries give a number of days: SELECT age('2008-02-05'::timestamp, '2008-01-01'::timestamp) AS "1 month" Produces: "1 mon 4 days" SELECT justify_days('2008-02-05'::timestamp - '2008-01-01'::timestamp) AS "1 month" Produces: "1 mon 5 days" Had I used June into July, these would have agreed at '1 mon 4 days'. Dave On Sat, Nov 8, 2008 at 4:12 AM, Gerhard Heift < [EMAIL PROTECTED]> wrote: > Hello, > > I want to get an interval in months from two dates: > > SELECT '2008-02-01'::timestamp - '2008-01-01'::timestamp AS '1 month' > > Here I want '1 month' and not '31 days' as answer. > > How can I do this? > > Regards, > Gerhard > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > > iD8DBQFJFVgNa8fhU24j2fkRAq0ZAJ925CHwchm/kZCwTTDcZF/QVXAlewCeMYGL > h3y0pxtiOiDV7pExYiEcSZ0= > =84G4 > -----END PGP SIGNATURE----- > > -- David Spadea President Spadea Enterprises, Inc http://www.spadea.net
