Validate date format in VBA

Validate that the value is in the format "mm/dd/yyyy"

Function ValidateDateFormat(dateValue As String) As Boolean

    If IsDate(dateValue) And Format(dateValue, "mm/dd/yyyy") = dateValue Then
            ValidateDateFormat = True
    End If

End Function

Validate that the value is in the format "YYYYMMDD"

Function ValidateDateFormat(dateValue As String) As Boolean

    If Len(dateValue) = 8 And IsDate(Format(dateValue, "@@@@/@@/@@")) Then
        ValidateDateFormat = True
    End If

End Function