How Math Can Tell You the Day of the Week for Any Date in History

With a dash of math, know the day of the week for any date on the calendar. The calendar is a mathematical object with regular patterns, such as leap years happening every four years. This results in your birthday increasing by one or two days as you go from one year to the next in a very predictable pattern. Using easy mnemonics, and by adding three numbers together -- derived from the month, date, and year -- the total yields the day of the week. This is a practical application of something called modular arithmetic -- in this case, we're adding and subtracting mod 7 because there are 7 days in a week. For more: http://lifehacker.com/5848651/how-to-... NOVA Facebook:   / novaonline   NOVA Twitter:   / novapbs   PRODUCTION CREDITS Videography & Production Ari Daniel Original Footage © WGBH Educational Foundation 2016 MEDIA CREDITS Music APM Additional Imagery Flickr/Dustin Liebenow Special Thanks Brunswick Junior High School Peter Stevens' Class