BAM Sample Programs

[SMcNeill]

Latest batch of programs: Added 2024-02

Your "Which weekday" program https://basicanywheremachine.neocities.o...ch_weekday has an error. Try the date 1-1-1800, which was a Wednesday. This program says it's Tuesday.

I have the same problem. I can never get any Zeller's congruence formulas to consistently produce correct results.

Code: (Select All)

Function GetWeekDay& (Day$) 'use MM/DD/YYYY format
    'From Zeller's congruence: https://en.wikipedia.org/wiki/Zeller%27s_congruence
    If CheckDayFormat(Day$) = 0 Then GetWeekDay = 0: Exit Function
    Dim As Long century, zerocentury, result
    Dim As Long MM, DD, YYYY
    MM = GetMonth(Day$): DD = GetDay(Day$): YYYY = GetYear(Day$)
    If MM < 3 Then MM = MM + 12: YYYY = YYYY - 1
    century = YYYY Mod 100
    zerocentury = YYYY \ 100
    result = (DD + Int(13 * (MM + 1) / 5) + century + Int(century / 4) + Int(zerocentury / 4) + 5 * zerocentury) Mod 7
    If result = 0 Then result = 7
    GetWeekDay& = result 'results are 1 to 7, from Sunday to Saturday
End Function

The above gives Wednesday as the proper result.  Use with the below for quick insertion of the weekday name:

Code: (Select All)

Function GetWeekDayName$ (Day$) 'use MM/DD/YYYY format
    Dim result As Long
    result = GetWeekDay(Day$)
    Select Case result
        Case 1: GetWeekDayName = "Sunday"
        Case 2: GetWeekDayName = "Monday"
        Case 3: GetWeekDayName = "Tuesday"
        Case 4: GetWeekDayName = "Wednesday"
        Case 5: GetWeekDayName = "Thursday"
        Case 6: GetWeekDayName = "Friday"
        Case 7: GetWeekDayName = "Saturday"
    End Select
End Function