I found a snippet about the history of the 4-5-4 cycle on the NRF website a while ago. I thought some readers may be interested. (This is lifted from their website...)

When and why was the 4-5-4 Calendar created?
The 4-5-4 Calendar, which is widely followed by retailers today, was derived in the 1930’s during an informal inter-industry discussion. Prior to and during the 1930’s, 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 4-5-4 Calendar was developed. Many stores began using the 4-5-4 Calendar in the 1940’s.

What is the purpose of the 4-5-4 Calendar?

The 4-5-4 Calendar serves as a voluntary guide for the retail industry and ensures sales comparability between years by dividing the year into months based on a 4 weeks – 5 weeks – 4 weeks format. The layout of the calendar lines up holidays and ensures the same number of Saturdays and Sundays in comparable months. Hence, like days are compared to like days for sales reporting purposes. The 4-5-4 Calendar also establishes Sales Release dates, which have historically been on the first Thursday following the month’s end. In recent years, however, as the flow of information has improved, more companies are releasing sales data earlier in the week.

What is a 53-week year?
Due to the layout of the 4-5-4 Calendar (52 weeks x 7 days = 364 days), which results in one remaining day each year, and the occurrence of Leap Year, it is sometimes necessary to add a 53rd week to the end of the calendar for sales reporting purposes only. This occurs approximately every five to six years, though this is not always the case. 1995, 2000, 2006, and 2012 are all 53-week years.