hi, when i substract two column contain date+time into a third column like this: =[Fin]-[Dbut] the result is bad: any idea? thanks. Marc.

Hello, Mathematical operations are different than the date-time operations. Please refer: http://msdn.microsoft.com/en-us/library/bb862071.aspx Hope this helps, Regards, Rohan --Please mark as "Answer" if the post resolve your issue--

hi, i try this formula: =TEXT([Fin]-[Debut],"h:mm") and i get this error: any idea?

Hi, I have tested it in my environment and it is working. Just follow the same: Insert this formula: =TEXT([Created]-[Modified],"H:MM")For data type, select Date and TimeFor date and time format, select Date and TimeClick OK Also check the log file if above steps don't work. Cheers, Hemendra-MCTS "Yesterday is just a memory,Tomorrow we may never see"

hi, i always have the same error. tanks.