Cron Time Zone Converter — schedules across zones

Unix cron (Vixie / cronie)

exact NATIVE

Five fields: minute hour day-of-month month day-of-week. Runs in the cron daemon’s local time (or CRON_TZ= on cronie).

Semantics & caveats (4)

If both day-of-month and day-of-week are restricted, the job runs when EITHER matches (OR). If either field starts with "*", both must match (AND) — so "*/2" in one field silently switches to AND.
Sunday is 0 or 7. Names (MON, JAN) are case-insensitive; ranges of names are accepted by Vixie and cronie.
Behaviour across DST follows cronie/Vixie: fixed-time jobs skipped by spring-forward run right after the change; on fall-back they run once. Jobs whose minute or hour field starts with "*" just follow the wall clock.
BusyBox, macOS and other crons differ in small ways (names, ranges, DST handling). Test on the real host.

DST policy

Fixed-time jobs skipped by spring-forward run immediately after the clock change; on fall-back they run once. Jobs whose minute or hour starts with "*" follow the wall clock (gap times never happen, repeated times run twice). source-derived

UTC-only platforms need two expressions

GitHub Actions schedules and AWS EventBridge rules run in UTC. A 09:00 Berlin job is 08:00 UTC in winter and 07:00 UTC in summer, so a single UTC cron is right only half the year. The Convert tab shows a UTC translation for each offset the zone uses, labelled with when it applies, rather than pretending one expression covers both. Where a platform supports zones — Kubernetes spec.timeZone, EventBridge Scheduler, Spring zone, Jenkins TZ=, cronie CRON_TZ — prefer that.

Type a zone name and it is checked against your browser’s IANA database. Abbreviations like EST or IST are rejected with suggestions because they are ambiguous and ignore DST; Etc/GMT+5 is flagged because its sign is inverted (it means UTC−5).

Try these

0 9 * * 1-5Berlin 09:00 to GitHub UTC
0 22 * * 1-5Crosses midnight in UTC
CRON_TZ=Asia/Tokyo 30 8 * * *cronie CRON_TZ

Questions

Does Kubernetes support CRON_TZ in the schedule?

No. Current Kubernetes versions reject TZ= or CRON_TZ= inside spec.schedule. Set spec.timeZone (stable since 1.27) instead.

Where does the time-zone data come from?

From your browser’s built-in IANA database via the Intl API. Results can differ slightly between browsers that ship older tz data, especially for recent rule changes.

Cron schedules across time zones

UTC-only platforms need two expressions

Try these

Questions