Calculate the weeknumber of a given date
#include <Date.au3>
_WeekNumberISO ( [$iYear = @YEAR [, $iMonth = @MON [, $iDay = @MDAY]]] )
| $iYear | [optional] Year value (default = current year) |
| $iMonth | [optional] Month value (default = current month) |
| $iDay | [optional] Day value (default = current day) |
| Success: | a week number of given date. |
| Failure: | 0 and sets the @error flag to non-zero. |
| @error: | 1 - faulty parameters values 99 - On non-acceptable weekstart value |
#include <Date.au3>
#include <MsgBoxConstants.au3>
MsgBox($MB_SYSTEMMODAL, "Todays weeknumber", "Todays weeknumber is " & _WeekNumberISO())