cronjob executing at wrong time

[Jeff Bauer <jbauer@rubic.com>]

I've got a server running Debian 3.0 r1.  A job that is
scheduled to execute at 8:01pm is executing at 2:01pm.
The cronjob entry runs as non-root user:

 1 20 * * 1-5  myjob

I have the server synchronized to a time source with ntpdate
and I've checked the local timezone.  The 'myjob' script itself
appears to run fine, just at the wrong time.

I've written some test scripts to echo `date` to a
log file via cron. The output agrees with the system
clock, but the scheduled cronjob runs at the wrong
time.

Kernel info:
 Linux trajan 2.2.20-idepci #1 Sat Apr 20 12:45:19 EST 2002 i686 unknown

I've been using crontab for many years, but I'm certainly
overlooking something quite obvious.  Any pointers to clues
will be most appreciated.  Thanks.

-Jeff