Tom, > timestamptz + interval is not immutable --- in fact, the particular > example you give (ts + '1 day') is certainly dependent on timezone > setting. Why not? Given that the time zone will be the same for both the timestamptz and the interval, how would the result not be immutable? -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance