*****Every minute
0 * * * * ?cron(* * * * ? *)OnCalendar=*-*-* *:*:00Every minuteSin ejecuciones próximas
| Campo | Valor | Significado |
|---|---|---|
| Minute | * | Every minute |
| Hour | * | Every hour |
| Day of Month | * | Every day of month |
| Month | * | Every month |
| Day of Week | * | Every day of week |
What is a Cron Expression?
A cron expression is a string of 5 (or 6-7 for Quartz) fields separated by spaces that defines a schedule for recurring tasks. Originating from Unix-like operating systems, cron expressions are now used across platforms — from Linux crontab to Java Quartz Scheduler, AWS CloudWatch Events, and Kubernetes CronJobs. Each field represents a time unit (minute, hour, day of month, month, day of week), and together they precisely describe when a job should run.
Standard vs Quartz Format
The Standard (Unix) format uses 5 fields: minute, hour, day-of-month, month, and day-of-week. The Quartz format (used in Java/Spring) adds a seconds field at the beginning, making it 6 fields. Quartz also introduces the ? character for "no specific value" in day-of-month or day-of-week fields. This tool supports both formats with automatic conversion between them.
How to Use
1. Choose your format (Standard or Quartz) using the toggle. 2. Use the visual Builder to select values for each field — or switch to Raw Editor to type directly. 3. Try Natural Language mode: type "every weekday at 9 AM" and get the cron expression instantly. 4. Review the output: expression with color-coded fields, human-readable description, and next execution times. 5. Explore the Timeline, Breakdown, and Convert tabs for deeper analysis.
Features
- Visual builder with radio-based field selection (every, step, range, specific values)
- 30+ ready-to-use presets organized by category (backup, cleanup, monitoring, notifications)
- Natural language parser — converts phrases like "daily at midnight" to cron expressions
- Next 5/10 execution simulator with timezone support and DST indicators
- Visual 24-hour and 7-day timeline showing execution points
- Expression breakdown table explaining each field
- Format converter: Standard ↔ Quartz, AWS CloudWatch, systemd timer
- Real-time validation with error/warning messages
- 100% client-side — your data never leaves the browser
Common Patterns
- */5 * * * * — Every 5 minutes
- 0 * * * * — Every hour at :00
- 0 0 * * * — Daily at midnight
- 0 9 * * 1-5 — Weekdays at 9 AM
- 0 0 1 * * — First of every month
- 0 2 * * 0 — Sundays at 2 AM
- */15 9-17 * * 1-5 — Every 15 min during business hours