Could you add something like this to the top of your code:

If IsNumeric(Target.Value) = False _
Or (Target.Value < 1 _
Or Target.Value 1500) Then
With Application
.EnableEvents = False
.Undo
.EnableEvents = True
MsgBox "no. no. no."
Exit Sub
End With
End If

(Check it before you do the conversion.)

Steve Rolls wrote:

I have the following code in a worksheet that makes
entering times very easy. Example: It converts an entry
of 1500 to 15:00. I need to limit the entry of times to
between 00:01 and 18:00. I need help with some additional
code to restrict entries to between these two times.
Thanks Steve

Private Sub Worksheet_Change(ByVal Target As Excel.Range)
Dim TimeStr As String

On Error GoTo EndMacro
If Application.Intersect(Target, Range
("d11:e500,h11:h500,h2:i5")) Is Nothing Then
Exit Sub
End If
If Target.Cells.Count 1 Then
Exit Sub
End If
If Target.Value = "" Then
Exit Sub
End If

Application.EnableEvents = False
With Target
If .HasFormula = False Then
Select Case Len(.Value)
Case 1 ' e.g., 1 = 00:01 AM
TimeStr = "00:0" & .Value
Case 2 ' e.g., 12 = 00:12 AM
TimeStr = "00:" & .Value
Case 3 ' e.g., 735 = 7:35 AM
TimeStr = Left(.Value, 1) & ":" & _
Right(.Value, 2)
Case 4 ' e.g., 1234 = 12:34
TimeStr = Left(.Value, 2) & ":" & _
Right(.Value, 2)
Case 5 ' e.g., 12345 = 1:23:45 NOT 12:03:45
TimeStr = Left(.Value, 1) & ":" & _
Mid(.Value, 2, 2) & ":" & Right(.Value, 2)
Case 6 ' e.g., 123456 = 12:34:56
TimeStr = Left(.Value, 2) & ":" & _
Mid(.Value, 3, 2) & ":" & Right(.Value, 2)
Case Else
Err.Raise 0
End Select
.Value = TimeValue(TimeStr)
End If
End With
Application.EnableEvents = True
Exit Sub
EndMacro:
MsgBox "You did not enter a valid time"
Application.EnableEvents = True
End Sub

--

Dave Peterson