I have seen this implimented with what were called "jobfiles" by the scripts in question. This was to enable testers to turn off each others cron jobs without having the necessary UNIX permissions. It worked like this: -

1) Cron job starts and looks for a "jobfile".
2) If found it looks for a command such as "Skip". This would cause it to clear its own crontab and exit.

Other commands such as "suspend [minutes]" or whatever can be implemented in the same way.