Some business applications use week numbers to categorize dates.
While this may be convenient in some applications, you need to be careful when using week numbers. If you need to use week numbers, you need to understand how they work and what they represent. An absolute week number is the 7 day period that a date falls within, based solely on the first day of the year, regardless of the day of the week. The absolute week number will always be between 1 and 53. Week 53 will have either one or two days, depending on whether the year is a leap year.