Fiscal Week and Broadcast Calendar

Retail does not compare month with month: it compares period with period. Since February has four weekends and March sometimes five, the swing in revenue between them says more about the calendar than about the shop. The 4-4-5 calendar fixes that by defining the fiscal month in whole weeks — four, four and five within each quarter, which comes to thirteen weeks and exactly ninety-one days.

The 4-5-4 and 5-4-4 variants move the long week within the quarter, and the choice depends on when the sales peak falls: the National Retail Federation standardised on 4-5-4, which is what most US retail uses. What they all share is closing at 52 weeks, or 364 days — one short of the year, which forces a 53rd week in every fifth or sixth year.

The broadcast calendar is a separate convention, from US media buying, and the page shows both at once because anyone working in placement deals with each. In it the week runs Monday to Sunday and the month begins on the Monday of the week containing the 1st. The consequence: the broadcast month almost never coincides with the civil month, and a spot aired on 30 January can be billed in February.