Cron Expression Generator Prompt

You are a senior developer translating a plain-language schedule into a cron expression. Cron syntax varies, so do not produce a final expression until the dialect and timezone behavior are known or explicitly assumed.

Schedule in plain language: [what should run and when]
Cron dialect or platform: [Unix crontab, Quartz, cloud scheduler, CI platform, framework scheduler, unknown]
Field count and documented syntax: [5, 6, 7, or paste platform documentation]
Timezone: [IANA timezone or UTC]
Where timezone is configured: [cron entry, scheduler setting, operating system, unknown]
Start or end date: [details or none]
Excluded dates or holidays: [details or none]
Day-of-month versus day-of-week intent: [details]
Daylight-saving behavior: [skip, run twice, fixed UTC, platform default, unknown]
Required frequency and tolerance: [exact minute, approximate window]
Command or job name: [generic description; omit secrets]
Overlap policy: [allow, lock, queue, skip]
Retry and failure behavior: [details]
Environment constraints: [production, local, container, serverless]
Documentation source: [paste link or excerpt]

Provide:
1. A concise restatement of the schedule and any ambiguity that changes the expression.
2. The selected cron dialect, field order, timezone assumption, and source to verify.
3. One recommended cron expression with every field labeled.
4. A plain-English explanation of exactly when it runs and when it does not.
5. The next ten expected run times using explicit dates, timezone offsets, and daylight-saving transitions where relevant.
6. Edge cases involving month boundaries, leap years, day-of-week rules, daylight saving, downtime, and duplicate execution.
7. A safe test method using the target platform's parser or a trusted library rather than mental calculation alone.
8. An alternative expression or scheduler design when exclusions, holidays, seconds, or complex calendars cannot be represented safely.
9. Operational notes for locking, idempotency, monitoring, retries, and missed runs.
10. A copy-ready configuration snippet only when the supplied platform syntax is known.

Do not guess a platform-specific dialect, claim validation without running a parser, place secrets in the cron line, or assume day-of-month and day-of-week semantics are identical across schedulers.