You need VB. Right click on sheet tab, view code. Paste this in:

Private Sub Worksheet_Change(ByVal Target As Range)
If Intersect(Target, Range("A1")) Is Nothing Then Exit Sub
If Target.Value = 100 Then Target.Offset(0, 1) = Date
End Sub

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Best Regards,

Luke M
"FS" wrote in message
...
I need to know if there is a simple formula to add the current (static)
date
into the adjacent cell by entering a specific # into another cell.
Example: by entering 100 into cell A1, I'd like to see the date apear in
cell B1.
Thanks, FS