Cron cheatsheet

Format

Min  Hour Day  Mon  Weekday

*    *    *    *    *  command to be executed

┬    ┬    ┬    ┬    ┬
│    │    │    │    └─  Weekday  (0=Sun .. 6=Sat)
│    │    │    └──────  Month    (1..12)
│    │    └───────────  Day      (1..31)
│    └────────────────  Hour     (0..23)
└─────────────────────  Minute   (0..59)

Operators

Operator	Description
`*`	all values
`,`	separate individual values
`-`	a range of values
`/`	divide a value into steps

Special strings

String	Description
`@reboot`	every rebot
`@hourly`	once every hour - same as `0 * * * *`
`@daily`	once every day - same as `0 0 * * *`
`@midnight`	once every midnight - same as `@daily`
`@weekly`	once every week - same as `0 0 * * 0`
`@monthly`	once every month - same as `0 0 1 * *`
`@yearly`	once every year - same as `0 0 1 1 *`

Examples

Example	Description
`0 * * * *`	every hour
`/15 * * *`	every 15 mins
`0 /2 * *`	every 2 hours
`0 18 * * 0-6`	every week Mon-Sat at 6pm
`10 2 * * 6,7`	every Sat and Sun on 2:10am
`0 0 * * 0`	every Sunday midnight

Crontab

# Adding tasks easily
echo "@reboot echo hi" | crontab

# Open in editor - optional for another user
crontab -e [-u user]

# List tasks - optional for another user
crontab -l [-u user]

# Delete crontab file - optional for another user
crontab -r [-u user]