Planned start and end dates

Hi,

What are the constraints for the planned start and end dates and how are they calculated.

I have a case where the planned duration is different from the planned end (minus) planned start. However, the data shown in the GANTT diagram is correct.

And how can we explain the planned end date is different from the validated end date.

Thanks for your help.

Thanks.

But still I can't understand why is the planned end date for the 22/05. The ressource used does't have any other affectation for the same periode. The point also is that when I affect another resource, the planned end date will be 25/05 and the calculated and shown planned duration is correct. How can we explain it. See 1st attached.

However, after making the calculation and then saving the activity, while affecting the 1st resource, I can get the correct result: P. duration = P. End - P. Start, but I can't understand why. see 2nd attachement.

Thanks for your help.