crontab -l
to obtain a list of programs scheduled to run
last line of output is the actual command that was given, which includes the schedule
save this last line so that cron can be restarted later

to stop cron do 'crontab -r'

to restart:
To get into the crontab editor you have to type in the command prompt
 setenv VISUAL vi
 setenv EDITOR vi
 crontab -e
 
 type in the one line of scheduling info, it uses vi editor

I have the following options attached below that can be used with 
'crontab' :

e 
edit a copy of the current user's crontab file, or creates an empty file 
to edit if crontab does not exist. When editing is complete, the file is 
installed as the user's crontab file. If a username is given, the 
specified user's crontab file is edited, rather than the current user's 
crontab file; this may only be done by a super-user. The environment 
variable EDITOR determines which editor is invoked with the -e option. The 
default editor is ed(1). Note that all crontab jobs should be submitted 
using crontab; you should not add jobs by just editing the crontab file 
because cron will not be aware of changes made this way.

-l 
list the crontab file for the invoking user. Only a super-user can specify 
a username following the -r or -l options to remove or list the crontab 
file of the specified user.

-r 
remove a user's crontab from the crontab directory.

