Sample Functions to Parse Numbers and Strings into Dates

MORE INFORMATION

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   Num2Date converts a number to a date.
				

   String2Date converts a string to a date.
				

Masks supported by Num2Date:

   MMDDYY    MMDDYYYY
   DDMMYY    DDMMYYYY
   YYMMDD    YYYYMMDD
				

Masks supported by String2Date:

   MMDDYY    MMDDYYYY   MM/DD/YY   MM/DD/YYYY   M/D/Y   M/D/YY   M/D/YYYY
   DDMMYY    DDMMYYYY   DD/MM/YY   DD/MM/YYYY   DD-MMM-YY   DD-MMM-YYYY
   YYMMDD    YYYYMMDD   YY/MM/DD   YYYY/MM/DD
				

Example

1. Create a new VBA project and add a Module.
2. Add the following code to the module:

         Function Num2Date (ByVal N As Long, ByVal Fmt As String) As Variant
           Select Case Fmt
             Case "MMDDYY"             '052793
               Num2Date = CDate(N \ 10000 & "/" & N \ 100 Mod 100 & _
                                "/" & N Mod 100)
             Case "MMDDYYYY"           '05271993
               Num2Date = CDate(N \ 1000000 & "/" & N \ 10000 Mod 100 & _
                                "/" & N Mod 10000)
             Case "DDMMYY"             '270593
               Num2Date = CDate(N \ 100 Mod 100 & "/" & N \ 10000 & _
                                "/" & N Mod 100)
             Case "DDMMYYYY"           '27051993
               Num2Date = CDate(N \ 10000 Mod 100 & "/" & N \ 1000000 & _
                                "/" & N Mod 10000)
             Case "YYMMDD", "YYYYMMDD" '930527   19930527
               Num2Date = CDate(N \ 100 Mod 100 & "/" & N Mod 100 & "/" & _
                                N \ 10000)
             Case Else
               Num2Date = Null
           End Select
         End Function
   
         Function String2Date (ByVal S As String, _
                               ByVal Fmt As String) As Variant
           Select Case Fmt
             Case "MMDDYY", "MMDDYYYY"      '052793   05271993
               String2Date = CDate(Left(S, 2) & "/" & Mid(S, 3, 2) & "/" & _
                                   Mid(S, 5))
             Case "DDMMYY", "DDMMYYYY"      '270593   27051993
               String2Date = CDate(Mid(S, 3, 2) & "/" & Left(S, 2) & "/" & _
                                   Mid(S, 5))
             Case "YYMMDD"                  '930527
               String2Date = CDate(Mid(S, 3, 2) & "/" & Right(S, 2) & "/" & _
                                   Left(S, 2))
             Case "YYYYMMDD"                '19930527
               String2Date = CDate(Mid(S, 5, 2) & "/" & Right(S, 2) & "/" & _
                                   Left(S, 4))
             Case "MM/DD/YY", "MM/DD/YYYY", "M/D/Y", "M/D/YY", "M/D/YYYY", _
                  "DD-MMM-YY", "DD-MMM-YYYY"
               String2Date = CDate(S)
             Case "DD/MM/YY", "DD/MM/YYYY"  '27/05/93   27/05/1993
               String2Date = CDate(Mid(S, 4, 3) & Left(S, 3) & Mid(S, 7))
             Case "YY/MM/DD"                '93/05/27
               String2Date = CDate(Mid(S, 4, 3) & Right(S, 2) & _
                                   "/" & Left(S, 2))
             Case "YYYY/MM/DD"              '1993/05/27
               String2Date = CDate(Mid(S, 6, 3) & Right(S, 2) & _
                                   "/" & Left(S, 4))
             Case Else
               String2Date = Null
           End Select
         End Function
   						

3. Run the project and then pause it.
4. You can test the function in the Debug or Immediate window:
   

   
         ?Num2Date(19980203, "YYYYMMDD")
         #2/3/98#
         ?String2Date("020398", "MMDDYY")
         #2/3/98#
   						

   
   or in code:
   

   Dim D1 As Date, D2 As Date
   D1 = Num2Date(19980203, "YYYYMMDD")
   D2 = String2Date("020398", "MMDDYY")
   						

NOTE: As with any date conversion function, if only 2 digits of the year are supplied, you have the potential problem of distinguishing dates in the 1900s versus the 2000s. This can result in problems when calculating intervals for loan repayments, and so forth, when comparing two dates in different centuries. If only 2-digit years are supplied, the conversion functions adhere to the default "smart century" assumptions of the version of VBA that you are using. If you want to alter this behavior, you can easily modify the expressions for the appropriate masks.