Cron Expressions — The Complete Guide with Visual Builder

Cron schedules power backups, queues, billing jobs, and cleaner scripts. The classic five-field Unix cron string looks cryptic until you learn the map.

The five fields

* * * * *
| | | | └ day of week (0–7, 0/7 = Sunday on many systems)
| | | └── month (1–12)
| | └── day of month (1–31)
| └── hour (0–23)
└──── minute (0–59)

Special characters

Char	Meaning	Example
*	every value	* * * * * every minute
,	list	0 8,12,18 * * *
-	range	0 9-17 * * * hourly during work hours
/	step	*/15 * * * * every 15 minutes

Patterns you will copy-paste

Schedule	Expression
Hourly at :00	0 * * * *
Daily midnight	0 0 * * *
Weekdays 08:30	30 8 * * 1-5
Every 6 hours	0 */6 * * *

Build visually → ZeroKit Cron Builder previews next run times in plain language.

Platforms differ slightly

Platform	Gotcha
GitHub Actions	UTC only in schedule
Vercel crons	UTC, declarative in config
Some AWS rules	may use six fields (seconds)

FAQ

Timezone?
Assume UTC on most cloud schedulers unless the product documents otherwise.

Sub-minute?
Classic cron's smallest step is one minute. Sub-minute needs another system.