If you've ever had a reminder fail because your agent was between heartbeats, this is the fix. It draws a hard line between casual polling (heartbeat) and precise scheduling (cron), with concrete patterns for "remind me in X minutes" using one-shot jobs. The janitor pattern alone is worth it: a recurring job that auto-deletes finished reminders so you don't end up with 50 ghost entries. Includes the full JSON payloads and a critical rule about wake modes that isn't obvious from the docs. Best for anyone running scheduled tasks or reminders and tired of debugging timing drift.
npx skills add https://github.com/sundial-org/awesome-openclaw-skills --skill cron-mastery