Just one dose per day is all that is recommended. There is really no need to split the dose. The timing of day also shouldn't matter much. I know some people like to dose preworkout, but in my experience it makes no difference on effects. Another thing is some people will get some stomach discomfort from DAA if taken on an empty stomach. It never bothered me, but it is something to keep in mind. As for duration, a normal length of time to get good results from D-test is 4-6 weeks. One large tub of D-test lasts 6 weeks, so with that you would be good to go