Asp Programming Code Examples Asp > Date Time Code Examples European Weeknumber European Weeknumber Function weeknummer (iYear, iMonth, iDay) dim thursdayofweek dim firstthursdayofyear dim MyDay dim dayofWeek dim thursdaysyear MyDay = DateSerial(iYear, iMonth, iDay) dayofWeek = Weekday(MyDay) if dayofWeek = 1 then thursdayofweek = dateadd("d", -3 , MyDay) else thursdayofweek = dateadd("d",(5 - dayofWeek), MyDay) end if thursdaysyear = Year( thursdayofweek ) firstthursdayofyear = first_thursday_of_year (thursdaysyear) weeknummer = (datediff("ww", firstthursdayofyear ,thursdayofweek) + 1) end Function function first_thursday_of_year (iYear) dim first_jan dim dayofWeek first_jan = DateSerial(iYear, 1, 1) dayofWeek = Weekday(first_jan) select case dayofweek case 1 first_thursday_of_year = dateadd("d", 4 ,first_jan) case 2 first_thursday_of_year = dateadd("d", 3 ,first_jan) case 3 first_thursday_of_year = dateadd("d", 2 ,first_jan) case 4 first_thursday_of_year = dateadd("d", 1 ,first_jan) case 5 first_thursday_of_year = first_jan case 6 first_thursday_of_year = dateadd("d", 6 ,first_jan) case 7 first_thursday_of_year = dateadd("d", 5 ,first_jan) End Select end function