'Description: Calculate difference between 2 particular dates 
'             and show the result in format: day(s), hr:min:sec
'             For example: 
'             The first date  = 01/03/2002 17:18:00 and 
'             The second date = 01/09/2002 09:42:30, then
'             the result will output --> 183 day(s), 16:24:30 
'             (183 days, 16 hours, 24 minutes, and 30 seconds).
'             You can use the DateDiff function belongs to VB6
'Author     : Masino Sinaga 
'Created    : Sunday, September 1, 2002
'Preparation: 1. Create a new standar exe project with 1 Form.
'             2. Add controls: 2 TextBoxes, 1 Label, and 1 Timer.
'             3. Copy this following code to the form editor form.
'-------------------------------------------------------------------

Option Explicit
 
Function CalcDiff2Dates(ByVal d1 As Date, _
                        ByVal d2 As Date) As String
  Dim Second As Long, Day As Long, Hour As Long
  Dim CompleteHour As String
 
  If d1 > d2 Then
     MsgBox "The first date must be lower than " & _
            "the second date!", _
            vbCritical, "Warning"
     Exit Function
  End If
 
  'Count the difference in seconds
  Second = DateDiff("s", d1, d2)
 
  'Calculate the hour by dividing with 3600
  '(backslash ("\") in order to get the Integer
  'without decimal value)
  Hour = Second \ 3600
 
  'If hour greater than 23
  'it means: more than 1 day
  If Hour > 23 Then
 
     'Calculate day by dividing with 24
     '(backslash ("\") in order to get the Integer
     'value without decimal value)
     Day = Hour \ 24
 
     'Calculate the hour duration in hh:mm:ss
     CompleteHour = Format((d2 - d1), "hh:mm:ss")
 
  Else 'If the hour less than or equal with 23      

     Day = 0   'assign the Day with zero value      

     'Calculate hour duration in hh:mm:ss
     CompleteHour = Format((d2 - d1), "hh:mm:ss")
 
  End If  
 
  If Day = 0 Then  'If less than 1 day

     'Get the final result
     CalcDiff2Dates = CompleteHour
 
  Else  'If day greater than 0, show the day duration     

     'Get the final result
     CalcDiff2Dates = Day & " day(s), " & CompleteHour
 
  End If
 
  Exit Function
 
End Function
 
Private Sub Form_Load()
  Timer1.Interval = 500
  Timer1.Enabled = True
  Text1.Text = "01/03/2002 17:18:00"
  'Text2.Text = "01/09/2002 09:42:30"
  Text2.Text = Now
End Sub
 
Private Sub Timer1_Timer()
  On Error GoTo ErrHandler
  Text2.Text = Now
  Label1.Caption = CalcDiff2Dates(CDate(Text1.Text), _
                      CDate(Text2.Text))
  Exit Sub
ErrHandler:
  MsgBox "Invalid date or format!", _
         vbCritical, "Error Date"
End Sub