What */30 * * * * means
On the hour and half hour. Good for jobs whose cost you want to keep down while still refreshing twice an hour.
In plain English, cron reads this as: every 30 minutes, every hour, every day.
Field-by-field breakdown
| Field | Value | Meaning |
|---|---|---|
| Minute | */30 | every 30 |
| Hour | * | every value |
| Day of month | * | every value |
| Month | * | every value |
| Day of week | * | every value |
Editing this schedule
To adjust this expression or explain a different one, open the full cron expression parser — it explains any crontab line, lists upcoming runs and breaks down each field as you type. New to the syntax? The practical guide to cron expressions walks through every field with worked examples.