Loading skill
Install any skill in seconds. Free to start, no credit card required.
Get Started Free →jayrha/cron-scheduler
Builds, validates, explains, and previews cron expressions across Vixie/POSIX cron, systemd timers, and cloud schedulers, with explicit handling of timezones, DST, the day-of-month/day-of-week OR-logic trap, and overlap/missed-run pitfalls.
Passed 20 of 22 test cases with the skill, and 19 of 22 without it.
2 fixed18 passed either way1 still failing1 broke
Tokens, turns and time describe resource use, not a dollar price.
One of 2 test cases the skill fixed. Same model, same prompt, with and without the skill.
Provide a classic cron expression for a job that runs every weekday at 9am.
| Checked | Without skill | With skill |
|---|---|---|
| Explicitly states the assumed timezone for the expression | Missed | Passed |
The instructions your model reads when the skill loads.
Translate human scheduling intent into correct cron expressions, explain existing expressions in plain language, preview the next fire times, and avoid the subtle traps (DOM/DOW OR-logic, timezone/DST drift, overlapping long-running jobs, missed runs on downtime). Covers classic Vixie/POSIX cron, plus the dialects used by systemd timers, Quartz, AWS EventBridge, Kubernetes CronJobs, and GitHub Actions.
Keywords: cron, crontab, cron expression, schedule, scheduler, scheduled job, */5, 0 9 * * 1-5, timezone, TZ, DST, daylight saving, day-of-week, day-of-month, systemd timer, OnCalendar, Quartz, EventBridge rate/cron, Kubernetes CronJob, GitHub Actions schedule, every N minutes, weekday, next run, overlap, concurrencyPolicy, flock.
OnCalendar, Quartz/Spring (6-7 fields with seconds + ?), AWS EventBridge (6 fields, year, requires ?), Kubernetes CronJob (5 fields, UTC by default), or GitHub Actions (5 fields, UTC only). See references/cron-syntax.md for the field tables per dialect.references/timezones-and-dst.md.references/cron-syntax.md. Prefer ranges and steps (9-17, */15) over enumerations when they read clearly.*), Vixie cron fires when EITHER matches, not both. This is the #1 silent bug. See the worked example in examples/build-and-explain.md.scripts/cronlint.py "<expr>" -n 5 to confirm it parses, see a plain-language breakdown, and list the next fire times. Always preview before delivering.references/scheduling-pitfalls.md.┌───────────── minute (0-59)
│ ┌─────────── hour (0-23)
│ │ ┌───────── day of month (1-31)
│ │ │ ┌─────── month (1-12 or jan-dec)
│ │ │ │ ┌───── day of week (0-7, 0 and 7 = Sunday, or sun-sat)
│ │ │ │ │
* * * * * command
Operators: * (all), , (list), - (range), / (step). Macros: @yearly @monthly @weekly @daily @hourly @reboot.
| Human request | Expression | Notes |
|---|---|---|
| Every 5 minutes | */5 * * * * | Not the same as "at minute 5" |
| At minute 5 of every hour | 5 * * * * | |
| Every hour on the hour | 0 * * * * | |
| Every weekday at 9am | 0 9 * * 1-5 | DOW only — safe |
test cases passed, vs 19 / 22 without
Published skills whose descriptions closely match this one, with their headline benchmark lift.
More skills from the same source and nearby in the registry, with their headline benchmark lift.