Ron Johnson <ron.l.johnson@cox.net> writes:
> What's the inverse? Say I have a DATE and a TIME, and want to
> create a TIMESTAMP with them?
Add 'em together, using the "date + time" or "date + timetz" operator:
regression=# select current_date + '11:57'::time;
?column?
---------------------
2006-07-30 11:57:00
(1 row)
regression=# select current_date + '11:57-04'::timetz;
?column?
------------------------
2006-07-30 11:57:00-04
(1 row)
See "Date/Time Operators" in the manual. I believe these operations
are SQL-standard.
regards, tom lane