What's the name of this week number algorithm?

Question

My customer wants to display week numbers as they show up in his wall calendar:

Week #1 starts on 1st January
Last week of the year (#53 or #54) ends on 31st December
All other weeks start on Monday and end on Sunday

(As a consequence, first and last weeks do not necessarily have 7 days.)

Does this week number algorithm have a name?

Clarification: I already have PHP code to calculate it, I'm just curious about whether this way of identifying weeks has a commonly accepted name.

Because that won't help me when looking for information and it won't help other programmers that'll see the code later. — Álvaro González, Jan 18 '12 at 10:28
Ok, how about `week number calculator`: http://www.merlyn.demon.co.uk/weekcalc.htm — Azodious, Jan 18 '12 at 10:30
One more for help: http://stackoverflow.com/questions/274861/how-do-i-calculate-the-week-number-given-a-date — Azodious, Jan 18 '12 at 10:30

score 2 · Accepted Answer · answered Jan 18 '12 at 13:29

There isn't one - that is a completely off-the-wall approach to week numbers. Weeks normally start either with Monday or Sunday when using the Gregorian Calendar. They do not start midway. This is not a criticism of your customer, but a comment on the fact that people invent new ways looking at date arithmetic. And get in trouble migrating to new systems.

RFC 3339

http://www.ietf.org/rfc/rfc3339.txt

What's the name of this week number algorithm?

1 Answers1