Routines Calendar view doesn't show triggers with multi-value cron fields

The root cause here is almost certainly in the cron parsing logic for the Calendar expansion — the parser that generates per-day occurrence times from a cron expression likely splits on the first hour value and stops, rather than iterating over the full comma-separated list.

The discriminating test: what happens with a step expression that generates multiple fire times? e.g. 0 9-17/4 * * 1-5 (fires at 9, 13, 17 on weekdays). If that also doesn't appear in Calendar view, the issue is in the occurrence expansion step, not comma-list parsing specifically. If step expressions work but comma lists don't, it's a parsing bug before expansion.

Quick diagnostic: Does the Calendar view show the correct single occurrence when you reduce to 0 9 * * 1-5? If yes, and swapping to 0 9,12 * * 1-5 makes it disappear entirely (not just show one), then the calendar expansion is treating the comma-separated list as an invalid expression rather than a multi-value field.

Worth noting that next_run_at being correctly populated in the API confirms the scheduling engine parses the expression correctly — only the Calendar UI rendering is broken. The fix is likely in the Calendar view's own cron-to-occurrence expansion, independent of the scheduling backend.

Update: Confirmed the issue is specifically caused by multi-value cron hour fields (comma-separated values like 9,12,16).

Test performed:

1. Trigger with cron 0 9,12,16 * * 1-5 → does NOT appear in Calendar view
2. Changed to 0 9 * * 1-5 (single value) → appears immediately in Calendar view
3. Changed to 0 15 * * 1-5 (different single value) → still appears fine

The trigger exists and runs correctly in all cases (visible in the "All" tab and via the API). It's purely a Calendar view rendering issue with comma-separated cron fields.

The root cause here is almost certainly in the cron parsing logic for the Calendar expansion — the parser that generates per-day occurrence times from a cron expression likely splits on the first hour value and stops, rather than iterating over the full comma-separated list.

The discriminating test: what happens with a step expression that generates multiple fire times? e.g. 0 9-17/4 * * 1-5 (fires at 9, 13, 17 on weekdays). If that also does not appear in Calendar view, the issue is in the occurrence expansion step, not comma-list parsing specifically. If step expressions work but comma lists do not, it's a parsing bug before expansion.

Quick diagnostic: Does the Calendar view show the correct single occurrence when you reduce to 0 9 * * 1-5? If yes, and swapping to 0 9,12 * * 1-5 makes it disappear entirely (not just show one), then the calendar expansion is treating the comma-separated list as an invalid expression rather than a multi-value field.

Worth noting that next_run_at being correctly populated in the API confirms the scheduling engine parses the expression correctly — only the Calendar UI rendering is broken. The fix is likely in the Calendar view's own cron-to-occurrence expansion, independent of the scheduling backend.

Fix on the way

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.