Thank you so much, actually this is what I have to do,
I have to recalculate for the last one and half year my activity from work and are many working times that I have to correctly know ! For example I work 15 hours per day but 5 are driving, 2 are work, 2 are waiting and others break ! I have to do this hour by hour and is very complicated to do this with the pen and paper!
I will try with the solution you gave me !