N° of the week from a date

[ggauny@live.fr]

Hi,

Thanks for encouragements ! I know that if the 01/01/yyyy biguin a thursday (jeudi), the n° of week is 1, if there is less than 4 days in the biguining year, the week is noted "0". Then at the end of the year we, sometimes, have a "53" week, wich is combinated with the following first week of the following YEAR+1.

In french it si more easy to explain,

On peut trouver W = 0 dans le cas du ou des premiers jours de l’année lorsque la première semaine (incomplète) de janvier a 1, 2, ou 3 jours ; ces quelques jours appartiennent alors a la dernière semaine, numérotée 52 ou 53, de l’année précédente.



De même, le 29 / 12 / m -si c’est un lundi- , le 30 / 12 / m -si c’est un lundi ou un mardi- , le 31 / 12 / m -si c’est un lundi, un mardi ou un mercredi- appartienent à la semaine 1 de l’année m + 1 ,

Sorry to write in french, but it is obligation for me in this case.

As an an example : on the official calendar of post in france, I can see that :

1/01/2015 is thursday, 2/02/2015 is friday, 3/01/2015 is saturday and 4/01/2015 is sunday, well there are at least 4 days then the week is officialy noted as n°1.
The last week of 2015 has 4 days (28,29,30,31 : monday, thuesday, wednessday and thursday) is noted of course n°53. On the other hand, in 2016 there will be only 3 days on biguining year (Friday 1, saturday 2 and sunday 3) so the first week of 2016 will be of course noted, officialy on french calendar, n° 0.

I've attempted to put photos of the calendar, but too bigs for our forum.

Good day

Gérard.