Calendars are sometimes the most difficult thing to design. I think the main reason is the complex set of variables that are needed to be handled. With each month comes a different number of days, a different starting day is always an obstacle too. Another difficult situation to some is the previous days in the first week (prior month) and then the days that are in the remaining days in the last week (next month’s days). Sometimes we tend to over think certain programming tasks. We think about how difficult it will be to figure all of these things out at once to make the perfect calendar. This leads me to the creation of this article, a simple way to use math to develop a calendar.