NRF | 4-5-4 Calendar - National Retail Federation | Home WHEN AND WHY WAS THE 4-5-4 CALENDAR CREATED?WHAT IS THE PURPOSE OF THE 4-5-4 CALENDAR?WHAT IS A 53-WEEK YEAR?HOW DOES NRF DETERMINE THE NEED FOR A 53RD WEEK?HOW ARE SALES DURING A 53-WEEK YEAR COMPARED TO THE SUBSEQUENT YEAR?The 4-5-4 Calendar, which is widely followed by retailers today, was derived in the 1930s during an informal inter-industry discussion. Prior to and during the 1930s, retailers used a straight calendar to report monthly sales. This calendar became problematic as Saturdays and Sundays became an increasingly large percentage of sales, since the number of weekends in a month varied year to year. A calendar that maintained the same number of weekends in comparable months was desired and the 4-See more on nrf 2018 Retail Accounting Calendar 4-4-5 - Free Printable Download FREE printable 2018 retail accounting calendar 4-4-5 and customize template as you like. This template is available as editable pdf / jpg / excel document.