How can I see my cron jobs?
You can use the cat, crontab and other Linux commands to view, list and display all cron jobs. The cron service searches its spool area (usually /var/spool/cron/crontabs) for crontab files (which are named after user accounts); crontabs found are loaded into memory.
Is there a GUI for crontab?
gnome-schedule is a graphical user interface that leverages the power of cron or anacron and at to manage a user's crontab file and provide an easy way to schedule tasks.
What does 30 * * * * mean in crontab?
*/30 * * * * your_command. this means "run when the minute of each hour is evenly divisible by 30" (would run at: 1:30, 2:00, 2:30, 3:00, etc) example #3. 0,30 * * * * your_command. this means "run when the minute of each hour is 0 or 30" (would run at: 1:30, 2:00, 2:30, 3:00, etc)