Getting Duration between two datetimes distributed correctly on time of occurence

Greg_Deckler thanks for the two links. I looked up more into the topic of "event in progress". At first I thought it is little bit similiar, but I cannot figure out how that will solve my problem. My OrderID's are by nature always closed. It already happened. It's just about the righ allocating of seconds to the right date columns. I hope someone encountered some smiliar problem. I I hope there is a workouround to this, since like the example when a duration is lasting more than several days, to return all the time duration solely on the starting date is totally wrong.