Planon allows for a period of 52/53 weeks as an accounting period as opposed to a proper year. This method is called the 4-4-5 calendar. By using this method, financial years always end on the same day (typically the end day of the week).

This calendar structure is common for some industries, such as retail, manufacturing, and parking.

In addition to using a monthly calendar, Planon also supports a 4-4-5 calendar. Based on this calendar Planon will generate weekly accounting commitments.