/cron Cron Expression Explainer
Paste a cron expression and get a plain-English description plus the next few UTC run times — so you can confirm that */15 or that Friday-only rule really does what you meant.
curl "curlhub.sh/cron?expr=*/15 * * * *"
Usage
With curl
curl --get --data-urlencode 'expr=*/15 * * * *' curlhub.sh/cron
curl "curlhub.sh/cron?expr=0 9 * * 1-5"
With the CLI
curlhub 'cron?expr=0 9 * * 1-5'
Structured output for scripts
curl -s --get --data-urlencode 'expr=*/15 * * * *' curlhub.sh/cron -H 'Accept: application/json'
Output
curl "curlhub.sh/cron?expr=*/15 * * * *"
Expression: */15 * * * *
Schedule: Every 15 minutes.
Next 5 runs (UTC):
2026-01-15T09:15:00Z
2026-01-15T09:30:00Z
2026-01-15T09:45:00Z
Parameters
| Input | What it does |
|---|---|
?expr= | The cron expression (URL-encode the spaces, or use --data-urlencode). |
Accept: application/json | Return the description and next-run list as JSON. |
Recipes
Sanity-check before you deploy a job
curl --get --data-urlencode 'expr=0 3 * * 0' curlhub.sh/cron
Reads back “At 03:00 on Sunday” with the next run times — catch an off-by-one before it ships.
Decode someone else’s crontab line
curlhub 'cron?expr=*/5 9-17 * * 1-5'