;------------------------------------------------------------------------------------------------------------------------------------------
; Note: This UDF "udfWeekOfYear" is obsolete.
; Replacement is: udfWeekOfYearISO
;------------------------------------------------------------------------------------------------------------------------------------------
#DefineFunction udfWeekOfYear (strYmdHms)
intJulianNow = TimeJulianDay (strYmdHms)
intJulianJan4 = TimeJulianDay (ItemExtract (1, strYmdHms, ":") : ":1:4")
intJulianDowJan4 = (intJulianJan4 + 5) mod 7 ; Range=0..6 = Sunday..Saturday
intJulianMonday = 1 + intJulianJan4 - intJulianDowJan4 - (7 * !intJulianDowJan4)
intWeek = (intJulianNow - intJulianMonday) / 7
intWeek = intWeek + (intJulianNow >= intJulianMonday)
Return intWeek
;..........................................................................................................................................
; The return value is an integer number in the range 0..53.
;
; ISO8601 defines Monday as the first day of any week.
; Week W01 of any year is the first week that contains January 4.
; In some years January 1, 2 and 3 could fall into week W52 or W53 of the previous year.
; The last few days of December could fall into week W01 of the following year.
;
; Detlev Dalitz.20010325.20090726.
;..........................................................................................................................................
#EndFunction
;------------------------------------------------------------------------------------------------------------------------------------------


; Test.

; Week of year.
strYmdHms01 = "1975:12:28:00:00:00"     ; Sunday
intWoy01 = udfWeekOfYear (strYmdHms01)  ; 52

strYmdHms02 = "1975:12:31:00:00:00"     ; Wednesday
intWoy02 = udfWeekOfYear (strYmdHms02)  ; 53

;   1975 Dezember
;        Mo Di Mi Do Fr Sa So
;   W49   1  2  3  4  5  6  7
;   W50   8  9 10 11 12 13 14
;   W51  15 16 17 18 19 20 21
;   W52  22 23 24 25 26 27 28
;   W53  29 30 31


strYmdHms03 = "1976:01:01:00:00:00"     ; Thursday
intWoy03 = udfWeekOfYear (strYmdHms03)  ; 1

strYmdHms04 = "1976:01:02:00:00:00"     ; Friday
intWoy04 = udfWeekOfYear (strYmdHms04)  ; 1

;   1976 Januar
;        Mo Di Mi Do Fr Sa So
;   W01            1  2  3  4
;   W02   5  6  7  8  9 10 11
;   W03  12 13 14 15 16 17 18
;   W04  19 20 21 22 23 24 25
;   W05  26 27 28 29 30 31


strYmdHms05 = "1977:01:02:00:00:00"     ; Sunday
intWoy05 = udfWeekOfYear (strYmdHms05)  ; 0

strYmdHms06 = "1977:01:03:00:00:00"     ; Monday
intWoy06 = udfWeekOfYear (strYmdHms06)  ; 1

;   1977 Januar
;        Mo Di Mi Do Fr Sa So
;   W00                  1  2
;   W01   3  4  5  6  7  8  9
;   W02  10 11 12 13 14 15 16
;   W03  17 18 19 20 21 22 23
;   W04  24 25 26 27 28 29 30
;   W05  31


strYmdHms07 = "2002:01:01:00:00:00"     ; Tuesday
intWoy07 = udfWeekOfYear (strYmdHms07)  ; 1

strYmdHms08 = "2002:01:07:00:00:00"     ; Monday
intWoy08 = udfWeekOfYear (strYmdHms08)  ; 2

;   2002 Januar
;        Mo Di Mi Do Fr Sa So
;   W01      1  2  3  4  5  6
;   W02   7  8  9 10 11 12 13
;   W03  14 15 16 17 18 19 20
;   W04  21 22 23 24 25 26 27
;   W05  28 29 30 31


strYmdHms09 = "2009:07:26:00:00:00"     ; Sunday
intWoy09 = udfWeekOfYear (strYmdHms09)  ; 30

strYmdHms10 = "2009:07:27:00:00:00"     ; Monday
intWoy10 = udfWeekOfYear (strYmdHms10)  ; 31

;   2009 Juli
;        Mo Di Mi Do Fr Sa So
;   W27         1  2  3  4  5
;   W28   6  7  8  9 10 11 12
;   W29  13 14 15 16 17 18 19
;   W30  20 21 22 23 24 25 26
;   W31  27 28 29 30 31

Exit