Cron Lab: Crontab Editor
Cron schedules, plain English
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Read and build cron schedules in plain English, free and offline. Cron Lab Pro adds conversion for Quartz, AWS, Kubernetes, Jenkins, Spring, and GitHub Actions.
Cron Lab reads and writes cron schedule expressions. Type one like "*/15 9-17 * * 1-5" and it tells you, in plain English, what it means, when it will run next in your timezone, and what might quietly break it.
Cron Lab is free. Four features (Convert, In words, backup and restore, and the Home Screen widget) are part of Cron Lab Pro, a one-time $0.99 in-app purchase.
Everything else listed below is free, and there is no subscription.
FREE
• Plain-English translation. Every expression becomes a clear sentence as you
type, with a field-by-field breakdown below it.
• Next runs. Accurate, DST-safe previews for any IANA timezone, in 12- or
24-hour time.
• Visual builder. Tap together a valid expression: every N minutes, specific
days, ranges, steps, and lists.
• Schedule doctor. Explains why an expression never runs (February has no
30th), warns about leap-year-only dates, and flags the day-of-month /
day-of-week OR rule that surprises almost everyone.
• Examples and reference. A categorized library of common schedules and a
built-in syntax cheat sheet.
• Your library. Save and label expressions, and browse recent history.
CRON LAB PRO (a one-time $0.99 in-app purchase)
• Convert. Turn a standard crontab line into Quartz, Spring @Scheduled, AWS
EventBridge, Jenkins, Kubernetes CronJob, or GitHub Actions. Handles the
tricky parts (seconds, day-of-week numbering, the "?" rule) and includes
copy-ready snippets, like the full CronJob YAML.
• In words. Type "every weekday at 9am" or "the 1st of the month at noon" and
get the matching expression.
• Backup and restore. Save your whole library to a JSON file and load it back.
• Home Screen widget. Pin a schedule to see its meaning and next run without
opening the app.
PRIVATE BY DESIGN
• No ads, no tracking, no account. Your schedules never leave your device.
• Works completely offline.
• Clean, minimal design with full light and dark mode.
• VoiceOver labels, legible contrast, large tap targets.
• Supports 5-field crontab and 6-field (seconds) expressions, names (JAN-DEC,
SUN-SAT), ranges, steps, lists, and @shortcuts (@daily, @reboot, and more).
Cron Lab Pro is a one-time $0.99 in-app purchase, not a subscription.
Fixes schedules that were read wrongly, including 'mon-fri 9am'.
Reads more of the ways people write schedules: "every quarter hour", "at 1730", "at 9 and 5 on weekdays", "each day at eight thirty".
Clearer plain-English descriptions, especially for time windows and repeating steps.
Says why it can't build a schedule when cron genuinely can't express it.
The developer, John Haas, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- John Haas
- Size
- 21.4 MB
- Category
- Developer Tools
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPad
Requires iPadOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Contains
Advertising
- In-App Purchases
Yes
- Cron Lab Pro $0.99
- Copyright
- © 2026 Jake Haas
