The REMIND command is used to cause a message to be sent to a user
at some future date or time.  The syntax is explained in the file
MAIL.BH[UP,DOC].  Here's an example.

REMIND/DATE=5-JAN-76/TIME=1200 FOO Don't forget our meeting.

To delete a reminder, type CANCEL<return> and
your pending reminders wil be listed and you will be allowed to
delete them selectively.