Adjusting Date Values by Keypress

Robert notes that in a Quicken date field, if he presses the plus or minus key the date increments or decrements by one day. He would like to create this same sort of effect in Excel.

This is a harder problem to approach than one might assume, particularly in Excel. Since an action needs to be taken upon the pressing of a particular key (in this case, the plus or minus keys), one would naturally assume that the OnKey method could be used. Consider the following examples:

Sub Start_OnKey()
    Application.OnKey "{+}", "Plus1"
    Application.OnKey "-", "Minus1"
End Sub

Sub End_OnKey()
    Application.OnKey "{+}"
    Application.OnKey "-"
End Sub

Sub Plus1()
    If IsDate(ActiveCell) And Not ActiveCell.HasFormula Then
        ActiveCell.Value = ActiveCell.Value + 1
    End If
End Sub

Sub Minus1()
    If IsDate(ActiveCell) And Not ActiveCell.HasFormula Then
        ActiveCell.Value = ActiveCell.Value - 1
    End If
End Sub

According to all the VBA documentation, the above should work just fine, once you run the Start_OnKey macro. Every time a plus or minus key is pressed, the appropriate procedure is run to either increment the date or decrement the date. The problem is, it won't work on some versions of Excel. Why? Because the plus key, when pressed, apparently puts some versions of Excel into a special "formula entry" mode that bypasses the normal keyboard buffer relied upon by OnKey. So while pressing the minus key while a cell containing a date is selected produces the desired result, pressing the plus key does not.

For those versions of Excel where the plus key is a problem, the only solution is to change the keystrokes to something else. For instance, you could change the keypresses so that Ctrl+u is used to increment the date and Ctrl+d is used to decrement the date:

Sub Start_OnKey()
    Application.OnKey "^u", "Plus1"
    Application.OnKey "^d", "Minus1"
End Sub

Sub End_OnKey()
    Application.OnKey "^u"
    Application.OnKey "^d"
End Sub