How to schedule a cron job every hour: the 0 * * * * pattern

How this is calculated

If you want the job to run at a different minute past the hour (say :30 for half-past), use 30 * * * *. To run only during business hours, constrain the hour field: 0 9-17 * * * runs at the top of every hour from 9 AM to 5 PM. For every 2 hours, use 0 */2 * * *. Most cron daemons also support the @hourly shortcut, which is equivalent to 0 * * * * and runs at the start of each hour.

Verdict

0 * * * * is the canonical every-hour pattern. Use the @hourly shortcut if your cron daemon supports it (Vixie cron, cronie, most Linux distributions). For more complex hourly schedules, constrain the hour field rather than trying to do it through the minute field.