hi,

modify hour per day and then change this number.

Hi Alain, 

I did that (Screenshot) after have to save but any change. 

no way this screen.

Parameters on the first pic you showed us.

Change the unit  hours by day,  then change the number of hours, then come back from day to hours. The Number of hours will be kept. it is a trick. It is not recommended to change the duration of work by day. Indeed, from now with this new unit, some workload will be missing on the past,  just to keep in mind reading reports and so on.

In addition to Alainforma's remark, you should not change hours per day parameter when some real work exist.
Keep in mind that Projeqtor stores work in days. So enter and display in hours is a conversion.

You have 5 hours per day.
If you have a user who entered 5 hours for a day in timesheet, projeqtor stored value 1 (1 day)
Now if you change hours per day to 10, same user reading his timesheet now sees 10 although he entered 5...