Five-Field Cron vs Quartz Cron

AIGClub Team

Different schedulers can use different field counts and special characters while still calling the syntax cron. Confirm the dialect before copying an expression.

Five-field Unix cron is minute hour day-of-month month day-of-week. Quartz commonly adds seconds first, may add a year last, and defines characters such as ?, L, W, and #. A parser must reject the wrong dialect rather than shift fields silently; AIGClub accepts only the documented five-field subset and common macros.

Read the five fields before previewing

For */15 9-17 * * MON-FRI, processing expands minutes 0,15,30,45, hours 9 through 17, and weekdays Monday through Friday. The preview starts after the selected minute, supports browser local time or UTC, returns at most 12 rows, and searches at most 366 days.

Reject shifted Quartz input

0 */5 9-17 * * MON-FRI has six fields and is rejected here rather than treating 0 as minute and */5 as hour. Quartz may also define ?, L, W, #, and a year field; none of those meanings should be guessed by a Unix parser.

Verify semantics with expected timestamps

Use a fixed timezone and start value as evidence. In UTC, 0 9 15 * MON starting at 2026-07-13 08:59 yields 2026-07-13 09:00 and 2026-07-15 09:00 because the implemented Unix day-of-month/weekday rule is OR. Compare these timestamps and actual scheduler logs with the target platform documentation.

Frequently asked questions

Why is 0 */5 * * * * rejected?
It is a six-field expression, usually with a seconds field. This tool parses five-field Unix cron only.
Can I use ? in Unix cron?
Usually no. ? is more common in Quartz-style expressions.
Does a five-field preview prove the job will run?
No. It proves only this parser's interpretation. Verify timezone, enabled state, permissions, environment, platform extensions, and actual scheduler logs.
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