Cron Expression Tool
Common Presets
每分钟
* * * * *每小时0 * * * *每天午夜0 0 * * *每周日午夜0 0 * * 0每月1日午夜0 0 1 * *工作日上午9点0 9 * * 1-5每5分钟*/5 * * * *每10分钟*/10 * * * *每30分钟*/30 * * * *每天0点和12点0 0,12 * * *Syntax Reference
| Symbol | Meaning | Example |
|---|---|---|
* | Any value | * * * * * |
, | List separator | 1,15 * * * * |
- | Range | 1-5 * * * * |
/ | Step | */5 * * * * |
How to Use
Expression Mode
Enter a Cron expression directly, and the tool will validate it in real-time, showing:
- Whether the expression is valid
- Human-readable execution description
- Next 10 execution times
Visual Builder
Select values for each field using dropdown menus to automatically generate the corresponding Cron expression.
Cron Expression Format
A standard Cron expression consists of 5 fields:
┌───────────── minute (0 - 59)
│ ┌───────────── hour (0 - 23)
│ │ ┌───────────── day of month (1 - 31)
│ │ │ ┌───────────── month (1 - 12)
│ │ │ │ ┌───────────── day of week (0 - 6, 0 = Sunday)
│ │ │ │ │
* * * * *
Common Examples
| Expression | Description |
|---|---|
* * * * * | Every minute |
0 * * * * | Every hour on the hour |
0 0 * * * | Every day at midnight |
0 9 * * 1-5 | Weekdays at 9 AM |
*/5 * * * * | Every 5 minutes |
0 0 1 * * | 1st of every month at midnight |
0 0 * * 0 | Every Sunday at midnight |
FAQ
What is a Cron expression?
A Cron expression is a time format for configuring scheduled tasks, made up of 5 fields (minute, hour, day of month, month, day of week). It precisely describes when a task runs and is widely used in Linux crontab and various job schedulers.
What do the 5 fields of a Cron expression represent?
From left to right: minute (0-59), hour (0-23), day of month (1-31), month (1-12), day of week (0-6, 0 = Sunday). For example, `0 9 * * 1-5` runs at 9 AM on weekdays.
How do I run a task every 5 minutes?
Use the expression `*/5 * * * *`, which runs every 5 minutes. `*/n` means every n units.
What is the difference between Cron and crontab?
Cron is the background service in Linux that runs scheduled tasks, crontab is the command-line tool for managing Cron jobs, and Cron expressions are the syntax that defines execution times.
Does it support 6 or 7 field Cron expressions?
This tool mainly supports the standard 5-field Cron expression. Some systems (like Spring) support an extra seconds or year field, but standard Linux crontab uses the 5-field format.
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