Question 1

What do the five standard cron fields mean?

Accepted Answer

They are minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-6, Sunday is 0). For example, '0 9 * * 1-5' runs at 09:00 Monday through Friday.

Question 2

When should I enable seconds?

Accepted Answer

Only schedulers that support six-field expressions (like Quartz or Spring) accept seconds. Enable it when your target scheduler uses the extended syntax; keep it off for standard cron.

Question 3

How are the next run times computed?

Accepted Answer

The tool scans forward minute by minute for up to one year and collects the next five matching timestamps in your local timezone. Day-of-month and day-of-week follow the standard cron rule: if both are restricted, a date matches when either one matches.

Question 4

Are next run times in my timezone?

Accepted Answer

Yes. Runs are computed in the browser's local timezone. If you deploy the schedule to a server, verify that the server timezone matches - most cron daemons interpret expressions in the server's local time.

Question 5

Why is my expression marked invalid?

Accepted Answer

Common causes: values outside the field range (e.g. minute 60), a step of zero, a range where the start exceeds the end, or stray characters. The tool highlights the offending field and shows the specific error.

Question 6

Does this match crontab.guru output?

Accepted Answer

The syntax, presets, and next-run semantics follow the same conventions as crontab.guru and the Vixie cron implementation. Minor wording differences may exist in the descriptions, but the expressions are interchangeable.

Cron 表达式生成器

表达式

关于 Cron 表达式生成器

功能亮点

Cron 表达式生成器

表达式

关于 Cron 表达式生成器

功能亮点

Cron 生成器 FAQ

标准 cron 的五个字段是什么意思?

什么时候该开启秒字段?

下次运行时间是怎么算的?

下次运行时间是本地时区吗?

为什么我的表达式被判为无效?

和 crontab.guru 的结果一致吗?