Here's how I would do it.
Instead of a t, I would just leave it blank, that way you tab through and don't even have to press a letter. (Is there any instance where you would tab through, leave it blank, and not want today's date?)
So whatever the field is, let's say it's a text box name txtDate, you're gonna want to set the on lost focus property event to some code.
Maybe something like this.
Code:
Private Sub txtDate_LostFocus()
If IsNull(Me.txtDate) Then
Me.txtDate = Date
End If
End Sub
You could also set it to "t" but you will have to change the validation to just general text, since t is not a date.
It would look like this
Code:
Private Sub txtDate_LostFocus()
If Me.txtDate = "t" Then
Me.txtDate = Date
End If
End Sub