There are only 5 weeks on the calendar but some months have 6

Around 21% of the time, a calendar month has 6 weeks. Since it only happens 21% of the time, we wanted to have our planners take advantage of the benefit that fits the majority. So, including only 5 weeks in the calendar gives more room in each box. For months with 6 weeks, we recommend carrying over into the following month's calendar.