Question

I am a bit confused when comparing StartDate and EndDate in my asp.net app.

EndDate:    10/1/2011
StartDate:  9/30/2011

The if statement below returns true, based on the date values above.

If strEndDate < strStartDate Then

I would think the If statement shoudl return false. The concept is supposed to be that if EndDate is earlier than StartDate, display an error message.

Answer 1

You should be using DateTime.Compare.

Dim date1 As Date = DateTime.Parse(strStartDate)
Dim date2 As Date = DateTime.Parse(strEndDate)
Dim result As Integer = DateTime.Compare(date1, date2)
Dim relationship As String

If result < 0 Then
   relationship = "is earlier than"
ElseIf result = 0 Then
   relationship = "is the same time as"         
Else
   relationship = "is later than"
End If

Console.WriteLine("{0} {1} {2}", date1, relationship, date2)
' The example displays the following output:
'    8/1/2009 12:00:00 AM is earlier than 8/1/2009 12:00:00 PM