cron / schedule handoff guide
Review cron dialect, timezone, and next run separately
A readable schedule is not proof that a job ran. Separate dialect, timezone, DST, next-run planning, and execution evidence in the handoff.
Fix the dialect first
Common cron uses five fields for minute, hour, day, month, and weekday. Quartz-style systems may use six fields with seconds or seven with a year. Confirm the runtime and library before interpreting an expression.
*/15 * * * * # 5-field: every 15 minutes; dialect and timezone still required
0 0/15 * * * ? # Quartz-style example: seconds field and ? marker| Boundary | What to check |
|---|---|
| Field count | Is it five-field cron or a Quartz six/seven-field form? Confirm seconds and year rules. |
| Weekday | Sunday 0/7, names, and day-of-month/day-of-week combinations vary by dialect. |
| Markers | ?, L, and W are dialect-specific. Reject them when unsupported. |
| Timezone | State an IANA name or other explicit target zone; do not rely on the host default. |
Review timezone and DST separately
A local time such as “02:30 every day” can be missing or duplicated during daylight-saving transitions. Confirm the target zone, effective date, and how the runtime handles gaps and overlaps. Do not promise a universal next-run answer.
A next run is a scheduler candidate. It is not a log, exit status, monitor event, or other execution evidence.
| Review | Pass condition |
|---|---|
| timezone | The target zone, reference time, and DST behavior travel with the expression. |
| next run | Label it as scheduled and do not describe it as executed or successful. |
| execution evidence | Verify logs, exit status, or monitoring evidence separately. |
Review cases
| case | outcome | check |
|---|---|---|
five-fields-local | reviewable | Five fields, target timezone, and runtime are explicit. |
dst-boundary | attention | Confirm missing or duplicated local times at the DST boundary. |
quartz-six-fields | dialect-check | Seconds or Quartz markers must not be passed to five-field cron. |
dow-seven | dialect-check | Confirm Sunday 0/7 and weekday-name semantics in the target runtime. |
unsupported-or-missing-zone | reject | Do not produce a next run for unsupported syntax or a missing timezone. |
Do not execute or paste secrets
This guide does not execute cron, call a scheduler, or connect to an external service. Use synthetic examples only; do not paste production commands, secrets, credentials, or internal hostnames.
Record expression, dialect, timezone, next-run plan, and execution-evidence reference as separate fields. A planned time alone is not a success report.