Time on should be calculated from the first injection or pill to the longest halflife of the last injection or last pill.
Ex. Deca for 10 weeks, actual on time should be 3.5 weeks from the last injection, becasue it will take that long for the deca to clear your system. Therefore your on for 13.5 weeks even though you only did injections for 10 weeks. Clomid would then start at the 13.5 week point but would not be considered on time.