Lets say you want to do something x times per day. Importantly, you want to start doing this thing at the begining of the day and end at the end of the day (start of period end of period). The first thing I think about when I want to start doing something like this is divide the day's hours by x. But I find you have to divide the day x-1, to land the activity at wanted times. Ex: I want to water a plant three times a day form 9 to 12. Intuitively I want to go 15hrs/3 = water every 5 hrs. But starting at 9, I would end up watering at the following times: 9am, 2pm, 7pm as supposed to wanting to do it at 9am, 12am, and in the middle of the day. 15hrs/3-1 however gives me 7.5. I would get what I want and start at 9, 4:30, and midnight. So the algorithm is to do the division by x-1 when wanting to place the intervals at the start. Why is that? Can someone elaborate on this? Throw some terminology around? Thanks.