May 10, 2010 falls on a Monday

-A A +A
By John Pawlak

Sept. 2, 1752 was a Wednesday. Adding fourteen days (two weeks), can you figure out what day of the week Sept. 16, 1752 was?

Halloween falls on a Saturday this year. July 4 next year will be on a Sunday.

If you own a perpetual calendar, you can look these dates up.

But without having a calendar handy, could you determine on what day of the week Valentines Day falls next year? Or Christmas? Your birthday? Uh, okay ... how about Easter Sunday?

It’s actually pretty easy to figure out these dates in your head and I thought it might be fun to write up the technique for anyone who might want to learn it.

The algorithm for calculating days of the week for a given date is called the Doomsday Algorithm. Why they didn’t call it the “Calculate Day of the Week Algorithm,” I can’t say. I prefer to just call it the D-day algorithm.

Let’s see how this works for the years 2009 and 2010. You rarely need to know the day of the week for any date more than two years out.

First, we define “D-day.” For any given year, the day of the week on which the last day of February falls is the D-day for that year.

If you subscribe to the newspaper, you receive FREE access to all the exclusive content of the web site! Simply register to receive uninterrupted access to our award-winning and in-depth local online content!

Renew Current or Past Subscription / Register for Online Subscription

If you currently subscribe or have subscribed in the past to the Los Alamos Monitor, then simply find your account number on your mailing label and enter it below.

Click the question mark below to see where your account ID appears on your mailing label.

Newspaper Acct. ID:
Street Address:
(exactly as it appears on the label)

If you are a subscriber and you do not know your account ID or don't have a copy of your newspaper available that shows the information on the address label you can click continue below to search for your account.

New Subscription/30 Day Free Trial Account

If you are new to the award winning Los Alamos Monitor and wish to get a subscription or simply gain access to our online content then please enter your ZIP code below and continue to setup your account.

ZIP Code:

Create a limited access account.
Register to participate in community forums, post on the community calendar, blog etc. This registration does not give you full access to read our award winning content, etc.

The Los Alamos Monitor | lacirculation@lamonitor.com | 505-662-4185
256 DP Road, Los Alamos, NM 87544
Office Hours are 8:00 a.m. to 5:00 p.m., Monday through Friday