Cron is the system scheduler on Unix/Linux/Mac operating systems. The ''crontab'' is the schedule of actions that the machine must keep. There are two types of crontabs in place on most systems: ''user crontabs'' and the ''system crontab''.
{{highlight|text=dates and times are critically important to the proper function of a computer. Be sure to setup and configure the Network Time Protocol Daemon [[NTP]]}}
== Avoid User Crons ==