>Hi all
>
>I have a field that store's time like this
>00:00:45 forty five seconds
>00:52:50 fifty two minutes and fifty seconds
>01:20:50 one hour and twenty minutes and fifty seconds
>
>And I want to do a sum on it to see how many hours was spend one something how I do it ?

To get only hours: Add the hours, minutes and seconds separately. Divide minutes by 60, and seconds by 3600, to convert everything to hours.

If you want to get hours, minutes and seconds separately in the sum:

Add hours, minutes and seconds separately. Divide seconds by 60, and pass the integral part to minutes (minutes = minutes + (seconds / 60)). Leave the remainder in seconds (for instance, seconds = seconds % 60).

Proceed similarly to add surplus minutes to the hours.