crontab every 6 hours code example

Example 1: cron every 3 hours

0 */3 * * *

Example 2: crontab every 30 minutes between hours

// from 08h to 17h (until 17:30)
*/30 8-17 * * *

// from 08h to 17h, at number '5' (until 17:35)
5,30 8-17 * * *