Re: pl/pgsql and returns timestamp type

Josh Berkus wrote:
>
> --Problem #1:  A TIMESTAMP minus another TIMESTAMP returns an
> --INTERVAL, not a TIMESTAMP.   See my paper on timestamps and
> --intervals on http://techdocs.postgresql.org/

Perhaps this one ?
FAQ: Working with Dates and Times in PostgreSQL
http://techdocs.postgresql.org/techdocs/faqdatesintervals.php