Cron example
Cron at 8:30 AM Monday to Friday
Half past eight, Monday through Friday. The minute field carries the 30 and the hour field carries the 8, in that order — which is the opposite of how the time is written and spoken. Reading a crontab as minute-then-hour is the single habit that prevents most scheduling mistakes.
By NaveenKumar T · Updated · 5-field crontab expression
What each field means
| Field | Value | Meaning |
|---|---|---|
| Minute | 30 | Minute 30 |
| Hour | 8 | Hour 8 |
| Day of month | * | Every day |
| Month | * | Every month |
| Day of week | 1-5 | Monday through Friday |
Next 5 run times
Computing the next runs in your timezone…
Minute first, hour second
The five fields are minute, hour, day of month, month, day of week. So 08:30 is written 30 8, not 8 30 — the latter would mean minute 8 of hour 30, which no parser will accept because hours only go up to 23. Getting a validation error for an impossible hour is the lucky outcome; the unlucky one is a time that happens to be valid in both orders, like 10 10.
Any minute from 0 to 59 is legal, so quarter past is 15, twenty to nine is 40 8, and 08:05 is 5 8 with no leading zero required. Cron accepts a leading zero too, but plain integers are the convention and read more cleanly in a crowded file.
Why 8:30 rather than 9:00
Half-past times are quietly better than the top of the hour on any shared system. The 00 minute of every hour is where log rotation, monitoring sweeps, cache expiry and every other crontab in the fleet collide; at :30 the machine is usually idle, so the job starts immediately instead of queuing behind a dozen others.
For anything humans consume, 8:30 also has a practical advantage over 9 AM: a report generated half an hour before the working day starts is already waiting when people sit down, and there is a thirty-minute buffer to notice and re-run a failure before anyone asks about it.
Related shapes
To add an afternoon run, extend the hour field into a list: 30 8,16 * * 1-5. To cover the whole working day at half past each hour, use 30 8-17 * * 1-5. To include weekends, drop the 1-5 and leave the day-of-week field as an asterisk.
If the job is a reminder tied to a meeting, remember cron will happily fire it on public holidays; the calendar check belongs inside the command. And if the team is spread across timezones, pin CRON_TZ so 08:30 means the same thing after the daylight saving transitions.
Build a variant of this schedule with dropdowns and check the next ten runs before you install it.
Open the cron generatorRelated cron examples
Browse every schedule on the cron expression generator, read the cron expression syntax guide for the rules behind the five fields, or the developer tools guides for the longer explanations.