I want accurate timer and alarm APIs with system-level notifications

I'm building a cooking app and need to set timers that are accurate to the second and can alert users through device push notifications when they complete. Timing accuracy is critical for precise cooking activities like baking, where even a few seconds can make a difference. The ability to use system-level notifications is essential to ensure alerts reach users even when the device media volume is muted.

Currently, web applications face several limitations when implementing timer functionality:

1. Background execution constraints: Timers may not fire accurately when the app is in the background or the device is sleeping
2. Notification limitations: The Notifications API requires user interaction and may not bypass system volume settings
3. Precision issues: JavaScript timers (setTimeout, setInterval) are not guaranteed to be precise, especially under heavy load or when the tab is backgrounded

What I need is a dedicated Web API that provides:

• Accurate timing: Guaranteed precision for timer completion, even in background states
• System-level alarms: Similar to native alarm clock apps, these should fire reliably at scheduled times
• Volume-independent notifications: The ability to alert users through system notifications that bypass media volume controls, similar to alarm and timer apps on mobile devices
• Persistent scheduling: Timers that survive page reloads and can be scheduled even when the app is closed

This would enable web apps to provide timer and alarm functionality that matches the reliability and user experience of native applications, particularly valuable for cooking apps, fitness timers, medication reminders, and other time-sensitive use cases.