See also

http://www.rondebruin.nl/isodate.htm

http://www.rondebruin.nl/weeknumber.htm


--
Regards Ron de Bruin
http://www.rondebruin.nl



"Amedee Van Gasse" wrote in message ...
JulieD shared this with us in microsoft.public.excel.misc:

Hi Ciara

from help
"If this function is not available, and returns the #NAME? error,
install and load the Analysis ToolPak add-in."

you must have the Analysis ToolPak add-in enabled on your machines,
the others in the office will need to do the same (tools / add-in,
tick analysis toolpak)

You should know that the results of the ATP-weeknum function are WRONG.

A correct formula for an ISO weeknum in the default 1904 based date
system is:

=INT((A1-SUM(MOD(DATE(YEAR(A1-MOD(A1-2,7)+3),1,2),
{1E+99,7})*{1,-1})+5)/7)

This one is also good, and also works in the 1900 based date system:

=1+INT((A1-DATE(YEAR(A1+4-WEEKDAY(A1+6)),1,5)+
WEEKDAY(DATE(YEAR(A1+4-WEEKDAY(A1+6)),1,3)))/7)

Read this page for more info:
http://www.cpearson.com/excel/weeknum.htm

An advantage of this formula is that you don't need to install the ATP
any more!

--
Amedee Van Gasse using XanaNews 1.17.3.1
If it has an "X" in the name, it must be Linux?

How To Ask Questions The Smart Way
http://www.catb.org/~esr/faqs/smart-questions.html
How to Report Bugs Effectively
http://www.chiark.greenend.org.uk/~sgtatham/bugs.html
Only ask questions with yes/no answers if you want "yes" or "no" as the
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http://homepages.tesco.net/~J.deBoyn...-with-yes-or-n
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