If the calendar is bound to a field, I assume you only want the calendar set
to the current date if you're entering a new record, so maybe something like
this:
Private Sub Form_Current()
If Me.NewRecord Then
EndDateCalendar.Value = Date
Else
EndDateCalendar.Value = Me.EndDateCalendar.Value
End If
End Sub

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Answers/posts based on Access 2000/2003