Question

I have an excel sheet (2003 and 2007) , in which I have got two columns FromDate and ToDate of the type DateTime in mm/dd/yyyy format.

There can be “n” number of records in the excel sheet.

I want to apply a validation , such that value of ToDate column should always be greater then equal to value of FromDate column, when the file is saved. If this is not the case then an error message should be prompted

Answer 1

EDIT: @brettdj made a great point – it may be the case that this already exists. If so, the following will show a message with each error (which will be super annoying if there are lots) and also debug.print it. Note that my setup here is the same as in the screenshots below. This will need to go into ThisWorkbook in the VBA Editor, and the code dropped into the BeforeSave event (this simply shows the errors and then continues to the save prompt):

Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)

Dim FromDate As Range
' Note that this assumes that the ToDate column has all values
' filled out. Otherwise it will stop short.
Set FromDate = Range("B2:B" & Range("A2").End(xlDown).Row)

' Iterate each cell, checking the value next to it and showing
' an error if the ToDate is > FromDate (ignore blank FromDates)
ErrorCount = 0
For Each Cell In FromDate
  If Cell.Value < Cell.Offset(0, -1) And Cell.Value <> "" Then
    ' Handle your error however you want - this just prints
    MsgBox "Error in row " & Cell.Row
    Debug.Print Cell.Row
    ErrorCount = ErrorCount + 1
  End If
Next Cell

' If we found any errors, cancel the save event
If ErrorCount > 0 Then
  Cancel = True
End If

End Sub

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If you are entering data…

Do you require it to use VBA? I only ask because you could do this without VBA using Data Validation:

1.) Set up your data, select the ToDate column (don’t include the column header) and click Data->Data Validation on the Ribbon (I’m using Excel 2007), change the Allow drop-down to Date, change the Data field to greater than or equal to and enter =A2 for the Start Date field.

Now enter a few values into column B, including ones that aren’t ‘correct’ (this includes any non-date [a date as defined by the cell format, in my case mm/dd/yyyy] as well as one that is before the ToDate). You will receive an error message (which you can also adjust if needed). Happy to modify the answer if you do in fact need/prefer to use VBA.