Cron jobs not running

[Michael Hopwood]

I cannot get the pi to run any cron jobs. I've tried multiple syntaxs, restarted the cron service, manually rebooted and nothing. Checked my uptime and it's greater than what it should be.

I did try having it run a job every 5 minutes and it worked flawlessly. Now I have it set to run every 6 hours and nothing, uptime is over 7 hours.

0 */6 * * * /sbin/reboot