The Anno Domini dating system and the Gregorian calendar that we now use are not zero-based numbering systems. There are no zeroth days, zeroth months or the zeroth year in these systems. That is because Europeans did not know zero as a number when they invented the AD dating system and the Roman calendar, the prototype of the Gregorian calendar. The numeral system we now use is, however, the zero-based decimal system. Identifying the time in reference to the current time system makes it difficult to calculate the functions whose variables include time. Although we should avoid unnecessary amendments, it is not desirable that we will continue to be bound by the numbering system which was formed when European mathematics was underdeveloped. Here I propose the best calendar that I can think of.