please god why aren't these predefined?

excel_parseDates.vba

' Expects a datetimestr in the format  "YYYYMMDD" with - or / or no separator
' Parses independently of local region, unlike VBA.DateTime.DateValue()
' Known-good on Excel for Mac Version 16.4
Function parseYYYYMMDD(dateTimeStr As String) As Date

    Dim normalized As String
    normalized = VBA.Strings.Trim(dateTimeStr)
    normalized = VBA.Strings.Replace(dateTimeStr, "/", "")
    normalized = VBA.Strings.Replace(normalized, "-", "")

    Dim datePart As String
    datePart = normalized

    Dim day As Integer, month As Integer, year As Integer
    year = VBA.Strings.Mid(datePart, 1, 4)
    month = VBA.Strings.Mid(datePart, 5, 2)
    day = VBA.Strings.Mid(datePart, 7, 2)
        
    Dim parsed_date As Date
    parsed_date = VBA.DateTime.DateSerial(year, month, day)

    parseYYYYMMDD = parsed_date
End Function

' Expects a datetimestr in the format  "DDMMYYYY" with - or / or no separator
' Parses independently of local region, unlike VBA.DateTime.DateValue()
' Known-good on Excel for Mac Version 16.4
Function parseMMDDYYYY(dateTimeStr As String) As Date

    Dim normalized As String
    normalized = VBA.Strings.Trim(dateTimeStr)
    normalized = VBA.Strings.Replace(dateTimeStr, "/", "")
    normalized = VBA.Strings.Replace(normalized, "-", "")

    Dim datePart As String
    datePart = normalized

    Dim day As Integer, month As Integer, year As Integer
    day = VBA.Strings.Mid(datePart, 3, 2)
    month = VBA.Strings.Mid(datePart, 1, 2)
    year = VBA.Strings.Mid(datePart, 5, 4)
        
    Dim parsed_date As Date
    parsed_date = VBA.DateTime.DateSerial(year, month, day)

    parseMMDDYYYY = parsed_date
End Function

' Expects a datetimestr in the format  "04-11-08" or "04/11/08"
' Parses independently of local region, unlike VBA.DateTime.DateValue()
' Known-good on Excel for Mac Version 16.4
Function parseMMDDYY(dateTimeStr As String) As Date

    Dim normalized As String
    normalized = VBA.Strings.Trim(dateTimeStr)
    normalized = VBA.Strings.Replace(dateTimeStr, "/", "_")
    normalized = VBA.Strings.Replace(normalized, "-", "_")

    Dim datePart As String
    datePart = normalized

    Dim dateParts As Variant, day As Integer, month As Integer, year As Integer
    dateParts = VBA.Strings.Split(datePart, "_")
    month = dateParts(0)
    day = dateParts(1)
    year = dateParts(2)
    
    Dim parsed_date As Date
    parsed_date = VBA.DateTime.DateSerial(year, month, day)

    parseMMDDYY = parsed_date
End Function

' Splits s on sep and returns ith part, trimmed
Function splitTake(s As String, sep As String, i As Integer) As String
    Dim parts As Variant
    parts = VBA.Strings.Split(VBA.Strings.Trim(s), sep)
    splitTake = VBA.Strings.Trim(parts(i))
End Function