Build, explain, validate, and preview cron schedules right in your editor.
A crontab.guru / crondle alternative inside VS Code. Get instant human-readable descriptions of any cron expression, see upcoming execution times, insert from a library of common schedules, and validate your expressions for potential issues.
Features
🗣️ Explain Any Expression
Type any cron expression and instantly get a plain-English description:
*/5 * * * *→ "At minutes 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, and 55 of every hour, every day"0 9 * * 1-5→ "At 09:00, on Monday through Friday"0 0 L * *→ "At 00:00, on the last day of the month"
⏭️ Next Run Calculator
See the next 10-20 execution times for any cron expression, with relative timestamps (+5m, +2h, +3d).
🧱 Preset Library
Insert common cron schedules with a single click from the Quick Pick menu. Includes 28+ presets:
- Every 5/10/15/30 minutes
- Hourly, every 2/6/12 hours
- Daily at midnight, 9am, twice daily
- Weekdays 9am, weekends 10am
- Every Monday/Friday
- Monthly 1st, quarterly, yearly
- Last day of month, 15th nearest weekday
- 3rd Thursday, last Friday
✂️ Snippets
Type cron- in any YAML or JSON file to get autocomplete snippets for common schedules.
📍 Explain at Cursor (Ctrl+Alt+C)
Place your cursor on a line containing a cron expression and run "Explain at Cursor" — the extension detects the cron pattern automatically.
🔍 Validate with Insights (Pro)
Pro feature — Go beyond basic validation. Get actionable insights about your cron expressions:
- OR semantics warnings — catch the #1 cron bug (day-of-month + day-of-week both restricted)
- Impossible schedule detection — "Day 31 in February will never run"
- Leap year warnings — February 29th only fires in leap years
- Step divisor analysis —
*/7doesn't divide evenly into 60 minutes - Midnight rush advice — avoid 00:00 scheduling spikes
- Frequency estimation — "≈8,760 runs per year" for capacity planning
Usage
- Press
Ctrl+Shift+P(orCmd+Shift+Pon Mac) - Type "Cron Helper" to see all commands
- Or use keyboard shortcuts:
Ctrl+Alt+C— Explain expression at cursorCtrl+Alt+I— Insert from preset library
Supported Cron Syntax
| Syntax | Example | Meaning |
|---|---|---|
* |
* * * * * |
Every value (wildcard) |
N |
5 * * * * |
Single value |
N,M,... |
1,15,30 * * * * |
List |
N-M |
0 9-17 * * * |
Range |
*/N |
*/15 * * * * |
Step (every N) |
N-M/S |
1-10/2 * * * * |
Range with step |
JAN-DEC |
0 0 * JAN-MAR * |
Named months |
SUN-SAT |
0 0 * * MON-FRI |
Named days |
L |
0 0 L * * |
Last day of month |
L-N |
0 0 L-3 * * |
N days before last |
NW |
0 0 15W * * |
Nearest weekday to N |
D#N |
0 0 * * 1#3 |
Nth weekday of month |
DL |
0 0 * * 5L |
Last weekday D of month |
Configuration
| Setting | Default | Description |
|---|---|---|
cronhelper.defaultRunCount |
10 |
Number of upcoming runs to show |
cronhelper.timezone |
UTC |
Timezone for run time display |
Pro Features
Upgrade to Pro for validation insights (impossible-schedule detection, OR-semantics warnings, frequency estimation, midnight rush advice) — $4/month (or $12/month for teams). Visit https://devforge.dev to get your license key.
Why this extension exists: Every developer writes cron expressions, but cron syntax is error-prone. The top VS Code cron extension has only 66K installs and is unrated. This extension brings the crontab.guru experience directly into your editor, where you write your schedules.
License
MIT