Unix Cron to AWS EventBridge Cron Converter
Paste a Unix cron expression to get the equivalent AWS EventBridge Scheduler cron expression — a year field appended, day-of-week renumbered, and exactly one of day-of-month/day-of-week set to "?" as EventBridge requires.
Close equivalent Covers the common case, but has documented behavioral differences.
- Unix cron
0 9 * * 1-5- AWS EventBridge cron
0 9 ? * 2-6 *
Main limitation: AWS EventBridge cron expressions have 6 fields (no seconds field at all, unlike Quartz) — minutes, hours, day-of-month, month, day-of-week, year — so this conversion only needs to append a year, not insert a seconds field.
Examples
Weekday mornings at 9am
| Unix cron | 0 9 * * 1-5 |
|---|---|
| AWS EventBridge cron | 0 9 ? * 2-6 * |
Unix Monday–Friday (1-5) becomes EventBridge 2-6 after renumbering; day-of-month becomes "?" since day-of-week is the restricted field.
First of the month at midnight
| Unix cron | 0 0 1 * * |
|---|---|
| AWS EventBridge cron | 0 0 1 * ? * |
day-of-month is restricted (1), so day-of-week becomes "?"; the year field is appended as a wildcard.
Caveats
Caveat
AWS EventBridge cron expressions have 6 fields (no seconds field at all, unlike Quartz) — minutes, hours, day-of-month, month, day-of-week, year — so this conversion only needs to append a year, not insert a seconds field.
Caveat
Like Quartz, EventBridge numbers day-of-week 1–7 with Sunday=1 and requires exactly one of day-of-month/day-of-week to be "?"; both requirements are applied automatically by this converter, the same way as for Quartz.
Caveat
EventBridge cron expressions are evaluated in UTC unless a time zone is explicitly configured on the schedule resource itself (outside the cron string) — double check your schedule's configured time zone, since the expression alone doesn't carry that information.
References
- crontab(5) — POSIX cron expression format (man7.org) — checked 2026-07-29
- AWS documentation — EventBridge Scheduler cron expressions — checked 2026-07-29
Last verified 2026-07-29.