WD97: How to Determine the Number of Days Between Two Dates

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To determine the number of days between two dates, using Visual Basic for Applications you can convert dates to serial numbers and subtract one number from the other.

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The following Visual Basic for Applications sample macro prompts for a date in the mm/dd/yy format, and returns the number of days between the current date and the specified date.

The DateValue() function converts a specified date, beginning with December 30, 1899, to a serial number.

Syntax: DateValue(DateText$)


   x = DateValue("12/30/1899")  ' returns 0 or zero
x = DateValue("12/31/1899") ' returns 1
x = DateValue("12/5/1992") ' returns 33943

The Sgn() function is used to determine if the difference between two dates is a negative(date in the past) or positive(date in the future) number.

   Sub DayDiff()
Dim sDate As String
Dim intNumDays As Integer
On Error GoTo errhandler
' Prompt for a date.
sDate = InputBox$("Enter a date in the mm/dd/yy format")
' Get difference between dates.
intNumDays = CInt(DateValue(sDate) - Now())
' Determine if difference is past or future.
If Sgn(intNumDays) = 1 Then
MsgBox "Days between " + sDate + " and today :" + CStr(intNumDays)
MsgBox "The date " + sDate + " was" + CStr(Abs(intNumDays)) _
+ " day(s) ago."
End If
If Err > 0 Then MsgBox "Please enter a valid date."
End Sub

For additional information, please see the following article in the Microsoft Knowledge Base:
173707 OFF97: How to Run Sample Code from Knowledge Base Articles


For more information about getting help with Visual Basic for Applications, please see the following article in the Microsoft Knowledge Base:
163435 VBA: Programming Resources for Visual Basic for Applications

Id. de artículo: 171044 - Última revisión: 07/13/2009 - Revisión: 1