~/cron-builder

Cron: weekdays at 9 AM

The cron expression `0 9 * * 1-5` fires Monday through Friday at 09:00. The most common business-hours schedule.

# expression

0 9 * * 1-5

Means: At 09:00 on every day-of-week from Monday through Friday.

→ Open in cron builder (pre-filled)

# common use cases

• Morning digest emails to the team.
• Business-hours data sync (avoid the weekend traffic patterns).
• On-call rotation reminders.

# next fires (sample)

• Mon 09:00
• Tue 09:00
• Wed 09:00
• Thu 09:00
• Fri 09:00

# pitfalls

• POSIX: 1-5 = Mon-Fri. Quartz/AWS: 2-6 = Mon-Fri (Sunday is 1, not 0). Translate before pasting.
• Business hours are timezone-dependent. Schedule in the team timezone via the cron-builder, or in UTC if your runner does not support timezone overrides.
• Holidays still fire. Add a check at the top of the job: `if (isPublicHoliday(today)) exit 0`.

# other patterns

• Cron: every 5 minutes — */5 * * * *
• Cron: every 15 minutes — */15 * * * *
• Cron: every hour — 0 * * * *
• Cron: daily at 3 AM — 0 3 * * *
• Cron: first of every month at midnight — 0 0 1 * *
• Cron: annually (Jan 1 at midnight) — 0 0 1 1 *

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