WD2000: Macro to Determine the Number of Days in a Specified Month (212545)

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For more information about how to use the sample code in this article, click the article number below to view the article in the Microsoft Knowledge Base: The following macro prompts for a date in mm/dd/yyyy format and prints the number of days in the specified month in a message box.

Sub Date_NumDaysInMonth()
   Dim iMon As Integer
   Dim sDate As String

PromptForDate:
   sDate = InputBox("Enter a date in the mm/dd/yyyy format")
   ' If Cancel was pressed, end macro.
   If sDate = "" Then Exit Sub
   ' If Date entered is not a valid date, display message.
   If Not IsDate(sDate) Then
      MsgBox "Please enter a valid date."
      GoTo PromptForDate
   End If
   ' The Month function returns the month number (1-12) of the date.
   Select Case Month(sDate)
      Case 4, 6, 9, 11
         sNumDays = "30"
      Case 2
         If Year(sDate) Mod 4 = 0 Then
            sNumDays = "29"
         Else
            sNumDays = "28"
         End If
      Case Else
         sNumDays = "31"
   End Select
   MsgBox Format$(sDate, "mmmm") & " of " & Format$(sDate, "yyyy") _
         & " has " & sNumDays & " days."
End Sub
				

The macro takes leap years into consideration when it computes the number of days in February. That is, this routine divides the year by 4; if the remainder is 0, there are 29 days in February of the year specified. Otherwise, there are 28 days in February of the year specified.