Trapping Cell Input BEFORE Cell Updates

Greetings,

I have a Worksheet that provides a cell for the user to enter a Date/Time.

The cell is formated as Date/Time.

I've had some feedback from users that it would be nice just to enter the time without a semi-colon to obtain the current date + the time they entered.

For instance, if they enter 2115, the cell would show the current date with time of 21:15,
i.e. 10/31/2011 21:15.

My problem is that if they enter 2115, the cell updates and formats the contents to 10/15/1905 00:00, THEN calls the WORKSHEET CHANGE event.

Is there a BEFORE CHANGE event that isn't documented?

Any other solutions?