;------------------------------------------------------------------------------------------------------------------------------------------
#DefineFunction udfGetCountDowInPeriod (strYmdHmsStart, strYmdHmsStop, intDayOfWeek)
intDayOfWeek = intDayOfWeek mod 7 ; For sure.
intDayOfWeekStart = (5 + TimeJulianDay (strYmdHmsStart)) mod 7 ; Day of week of the starting date.
Return (TimeDiffDays (strYmdHmsStop, strYmdHmsStart) + intDayOfWeekStart - intDayOfWeek + 7 * (intDayOfWeek >= intDayOfWeekStart)) / 7
;..........................................................................................................................................
; This UDF "udfGetCountDowInPeriod" returns the number of occurrences of the given day of week within the given date period.
;
; Parameters:
; strYmdHmsStart ... Starting date (as WinBatch DateTime string DT-10 or DT-19).
; strYmdHmsStop .... Stopping date (as WinBatch DateTime string DT-10 or DT-19).
; intDayOfWeek ..... Day of the week (as integer number in the Julian date system).
;                    0 = Sunday, 1 = Monday, 2 = Tuesday, 3 = Wednesday, 4 = Thursday, 5 = Friday, 6 = Saturday.
;
; Note: Starting date must be less than stopping date.
;
; (c)Detlev Dalitz.20120102.
;..........................................................................................................................................
#EndFunction
;------------------------------------------------------------------------------------------------------------------------------------------


; Test1.
; Prepare the period of time.
intDaysDiff = 16 ; Next 16 days.
strYmdHmsStart = TimeYmdHms () ; Today.
strYmdHmsStop = TimeAdd (strYmdHmsStart, "0:0:" : intDaysDiff : ":0:0:0") ; Starting date plus some days into the future.

; Set the day of week to search for.
intDayOfWeek = 3 ; Julian days: 0=Sunday, 1=Monday, 2=Tuesday, 3=Wednesday, 4=Thursday, 5=Friday, 6=Saturday.

; Result. The number of the given day of week between starting date and stopping date.
intDowCount1 = udfGetCountDowInPeriod (strYmdHmsStart, strYmdHmsStop, intDayOfWeek)


; Test2.
; Prepare the period of time.
strYmdHmsStart = "2009:02:01"
strYmdHmsStop = TimeYmdHms ()
strDateTimeDiff = TimeDiff (strYmdHmsStop, strYmdHmsStart)

; Set the day of week to search for.
intDayOfWeek = 0 ; Julian days: 0=Sunday, 1=Monday, 2=Tuesday, 3=Wednesday, 4=Thursday, 5=Friday, 6=Saturday.

; Result. The number of sundays since starting date until today.
intDowCount2 = udfGetCountDowInPeriod (strYmdHmsStart, strYmdHmsStop, intDayOfWeek)

:CANCEL
Exit