croner

Croner is a tiny cron expression parser and scheduler for JavaScript and TypeScript. No external dependencies, no system cron, no database. It runs in your Node.js process, Deno, Bun, or even the browser.

TypeScript, MIT. The selling point is zero dependencies and correctness. It handles standard cron syntax plus extensions like seconds-level precision and the `L` flag (last day of month). It's timezone-aware out of the box, which is the thing that trips up most cron libraries.

Fully free. No paid tier, no cloud service. It's a library. You npm install it and call it from your code. Solo to large teams: free. The library weighs almost nothing and does exactly one thing well.

The catch: croner runs inside your process. If your app crashes, your schedules stop. For production workloads that absolutely cannot miss a scheduled run, you need a proper job queue with persistence (BullMQ with Redis, or a system-level cron job. Croner is perfect for in-process scheduling where a missed run isn't catastrophic. It's not a replacement for distributed job infrastructure.