Guido,

> Thanks, that works. Is it possible to cast the duration back to TIME. For example,
> I have 5400 sec and I want display the value as 01:30.

you don't want a time, you want a duration formatted as "hh:mm"; that's
not quite the same thing. Anyway, it can look the same if you stay under
24 hours (86400 seconds, that is); try:

select cast('00.00.00' as time) + 5400 from rdb$database

If you need to display durations longer than 24 hours, you'll have to
resort to custom processing (SP or UDF) because a TIME datatype simply
won't do.
Ciao
--
____
_/\/ando