> I have two TIMESTAMP fields CHECKIN and CHECKOUT...I need to calculate
> the duration between them to use in report and also get a TOTAL of all
> durations...
>
> How do i SELECT a duration in propert format, like 01:20...
>
> I tried CAST(CHECKOUT - CHECKIN AS TIMESTAMP) but i have conversion
> error...
>
> Thanks.

durations are not TIMESTAMPs.
subtract them by all means but be aware that the difference is in days
(whole numbers) and decimals parts of a day.
you then calc the resultant duration yourself
Alan