A typical message will look like this:
02/21 17:00
Time to Go Home!

The program reads the time stamp, and if the current time is later than
the time stamp (but no more than 2 months later), it will print out the message
in a window, beep loudly, and then change the line to look like this:

**/21 17:00
Time to Go Home!

The time stamp must be of the form: <month>/<day>  <hour>:<minute>
where <hour> is given by a 24-hour clock.  The program will then
display in a window the line immediately following the time stamp.  
Conceivably, the program could be changed to print out more than one line,
but all urgent-type messages I can ever think of are all one line long.
Also, the window will disappear if you click the left button on it or
if you get new mail (or if you remove mail from your usr/spool/mail file.