How to Calculate the Number of Weekdays in a Year

Everybody's working for the weekend. If they're lucky, they might get 53 of them in a year.

If you work Monday to Friday, 9 to 5, it seems like the weekends go by in a flash, while the working week drags on and on. You might wonder just how many weekdays you work every year. It's easy to figure out.

Instructions

1. Determine whether or not the year is a leap year. Leap years keep our standard 365-day year in sync with the actual period of Earth's revolution around the sun, which actually takes just a little bit longer than one year. Adding one day every four years keeps it almost, but not quite, in sync. It overcompensates a little bit, so some leap years skip. If the year is evenly divisible by four, it is a leap year, unless the year is evenly divisible by 100, but not by 400. So, for example, 2000 and 2012 are leap years, but 2100 will not be. If it's a leap year, there are 366 days in the year. If not, there are 365.

2. Determine what day of the week the year starts with. There are going to be a total of 53 of these days. If it's a regular year, there will be 52 of every other day. If it's a leap year, there also will be 53 of the day following the first day. For example, if the first day of the year is a Monday, and it's a leap year, there will be 53 Mondays and 53 Tuesdays, and 52 of every other day.

3. Add the number of Saturdays and Sundays together, and subtract the total from 365 for a regular year, or from 366 for a leap year. The remainder will be the number of weekdays. The year 2011 started on a Saturday. It's not a leap year, so there are 53 Saturdays and 52 Sundays (105 weekend days total), which calculates to 365-105=260.

References

• APCS Teacher; Calendar Logic
• How To Calculate The Weekday For Any Date On The Julian Or Gregorian Calendar
• Time and Date; Calendar for year 2011 (United States)