Cron Job Every Hour

The expression

0 * * * *  /path/to/command
@hourly    /path/to/command

Fixing the minute field to 0 and leaving the hour as * means "at minute 0 of every hour" — once per hour, at the top of the hour, 24 times a day. The @hourly nickname expands to exactly 0 * * * *, so use whichever reads better in your crontab.

A frequent mistake

Newcomers sometimes write * * * * * hoping for hourly, but that runs every minute. The trick is that an hourly job must pin the minute field to a single value. If you want it to run at half past instead, use 30 * * * *.

Every N hours

• 0 */2 * * * — every 2 hours (00:00, 02:00, 04:00 …).
• 0 */6 * * * — every 6 hours (00:00, 06:00, 12:00, 18:00).
• 0 9-17 * * 1-5 — top of each hour, 9am–5pm, weekdays.
• 0 8-20/4 * * * — at 8am, 12pm, 4pm and 8pm.

Note that step values on the hour field always count from 0, so */5 on hours yields 0, 5, 10, 15, 20 — which does not divide evenly into the day. When you need clean intervals, prefer 2, 3, 4, 6, 8 or 12.

Spreading top-of-hour load

Because so many jobs fire at 0 * * * *, the top of the hour can become a load spike. Shifting the minute — for example 7 * * * * or 23 * * * * — keeps the hourly cadence while moving your job off the crowded :00 mark. Use the generator to confirm exactly when your chosen expression will fire next.