Register Cron Trigger schedules for a Cloudflare Worker and implement, test, and observe its scheduled() handler

Documented steps

1. Add cron schedules to wrangler.toml: crons = ["*/3 * * * *", "0 15 1 * *"], or in wrangler.jsonc as "triggers": {"crons": [...]}. For environment-specific schedules, nest under [env.<name>] in TOML.
2. Implement the handler in the Worker entrypoint: export default { async scheduled(controller, env, ctx) { ctx.waitUntil(doWork()); } }. controller exposes cron (the matched expression) and scheduledTime.
3. Deploy with npx wrangler deploy so the schedule registers. Cron expressions use standard 5-field syntax at one-minute granularity and are evaluated in UTC.
4. Test locally with npx wrangler dev, then trigger the handler manually: curl "http://localhost:8787/cdn-cgi/handler/scheduled". Pass ?cron=*+*+*+*+* to simulate a specific expression, ?time=<ms> to override the scheduled time, and ?format=json for structured output.
5. Verify the schedule registered under the Worker's Triggers > Cron Triggers section in the dashboard.
6. Monitor executions in the dashboard Cron Events panel (retains the 100 most recent invocations) for quick debugging, or in Workers Logs for longer retention and structured inspection.
7. For programmatic or long-term observability, query execution metrics through the GraphQL Analytics API rather than the dashboard's limited history.
8. Budget the work against CPU limits: 10 ms CPU per Cron Trigger on Workers Free; on Workers Paid, 30 seconds CPU for schedules with an interval under 1 hour and up to 15 minutes CPU for intervals of 1 hour or more.
9. Official documentation verified for this route: https://developers.cloudflare.com/workers/configuration/cron-triggers/ | https://developers.cloudflare.com/workers/platform/limits/