Week() does not return the correct value

[mirkado227]

SET FDOW TO 2  && week starts with monday
SET FWEEK TO 1 && The first week contains January 1st

? WEEK({31.12.2006})     && returns 1 but should return 53
? WEEK({31.12.2006},1)   && returns 1 but should return 53
? WEEK({31.12.2006},1,2) && returns 53

It seems, that the set instructions (FDOW and FWEEK) has no effect. Do I make an error in reasoning?

 

[mirkado227]

With 31.12.2005 I got another strange result:

SET FDOW TO 2  && week starts with monday
SET FWEEK TO 1 && The first week contains January 1st

? WEEK({31.12.2005})     && returns 53 (correct)
? WEEK({31.12.2005},1)   && returns 53 (correct)
? WEEK({31.12.2005},1,2) && returns 1  (incorrect)

 

[Mike Gagnon]

? WEEK({31.12.2005},1,2) && returns 1 (incorrect)

Why would you say this is wrong? Your code is asking "what is the week number that contains January first (first parameter) and starts on a monday (second parameter)".

Mike Gagnon

If you want to get the best response to a question, please check out FAQ184-2483 first.
ReFox XI (www.mcrgsoftware.com)

 

[mirkado227]

Hi Mike

Yes, you are right. I interpreted the week-funktion with this parameteres wrong.
But: there cannot be a 53th week of a year. Is this correct?

 

[Mike Lewis]

ere cannot be a 53th week of a year

Yes, there can.

Week 52 could end on day 364. So, day 365 would be in week 53.

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

My sites:
Visual FoxPro (www.ml-consult.demon.co.uk)
Crystal Reports (www.ml-crystal.com)

 

[Olaf Doschke]

An often overseen fact is, the settings for FDOW and FWEEK only take effect, if you pass 0 as the corresponding parameters in eg the WEEK() function (see help on WEEK, DOW, etc.):

SET FDOW TO 2  && week starts with monday
SET FWEEK TO 1 && The first week contains January 1st

? DOW({^2005-12-31},0) && returns 6 = saturday (respects FDOW=2!)
? DOW({^2005-12-31}) && returns 7 = saturday (because FDOW = 1 = sunday is assumed!)

* so 1st January 2006 is sunday and so week 1 of 2006 goes 
* from monday, 26th December 2005 to sunday, 1st January 2006.

* these three calls are equal now with FDOW=2 and FWEEK=1:
? WEEK({^2005-12-31},0,0) && returns 1 (correct)
? WEEK({^2005-12-31},1,0) && returns 1 (correct)
? WEEK({^2005-12-31},1,2) && returns 1 (correct)

If you omit 0 as parameter, foxpro will use standard values of 1 as FDOW and 1 as FWEEK, not what you set with SET FDOW and SET FWEEK! So in your case your first 2 calls really had other parameters (both 1) than the last full call (with parameters 1,2).

With January 1st being part of week 1 - week 1 will mostly begin in the previous year, so you seldom (or never?) have a 53rd week. Standard of german calendars on the other side is is FDOW 2 and FWEEK 2. Especially with this setting of FWEEK, there can rather often be a 53rd week.

Bye, Olaf.