2013 CALENDAR WITH WEEK NUMBER ISO

2017 is restated for comparability to 2018). How are sales during a 53-week year compared to the subsequent year?įor comparability purposes, the NRF 4-5-4 Calendar restates a 53-week year in the subsequent year (ex. However, in 2017 there were four days remaining in January so a 53rd week was added on to the end of that year. For instance, if you look at the 4-5-4 Calendar for 2016-2018, you will see that in 2016 there were only three days remaining in January after the 52nd week (January 29-31). If, after laying out the entire 52-week calendar for any given year, there are four or more days left in January during the 53rd week, then a 53rd week is added. How does NRF determine the need for a 53rd week? This occurs approximately every five to six years, though this is not always the case. What is a 53-week year?ĭue 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. In recent years, however, as the flow of information has improved, more companies are releasing sales data earlier in the week. The 4-5-4 Calendar also establishes Sales Release dates, which have historically been on the first Thursday following the month’s end. Hence, like days are compared to like days for sales reporting purposes. The layout of the calendar lines up holidays and ensures the same number of Saturdays and Sundays in comparable months. 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. What is the purpose of the 4-5-4 Calendar? Many stores began using the 4-5-4 Calendar in the 1940s. A calendar that maintained the same number of weekends in comparable months was desired and the 4-5-4 Calendar was developed. 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. Prior to and during the 1930s, retailers used a straight calendar to report monthly sales. The 4-5-4 Calendar, which is widely followed by retailers today, was derived in the 1930s during an informal inter-industry discussion. Starting in Excel 2013, there is a new function called ISOWEEKNUM.įor more details, see Ron de Bruin's nice write-up on Excel week numbers.When and why was the 4-5-4 Calendar created?

2013 CALENDAR WITH WEEK NUMBER ISO

Starting with Excel 2010, you can generate an ISO week number using 21 as the return_type: =WEEKNUM(date,21) ISO week numbers, start on the Monday of the first week in a year with a Thursday. This means that the first day of the year for ISO weeks is always a Monday in the period between Jan 29 and Jan 4.

With a return_type of 2, week 1 begins on January 1, and week 2 begins on the next Monday. See the WEEKNUM page for more information. WEEKNUM takes two arguments: a date, and (optionally) return_type, which controls the scheme used to calculate the week number.īy default, the WEEKNUM function uses a scheme where week 1 begins on January 1, and week 2 begins on the next Sunday (when the return_type argument is omitted, or supplied as 1). The WEEKNUM function starts counting with the week that contains January 1. The WEEKNUM function takes a date and returns a week number (1-54) that corresponds to the week of year.

2013 calendar with week number