It is accurate enough for everyday timing but not for scientific measurement.

Can I use it for billable work?

Yes for quick tracking, but export/history can be added next.

Does it store history?

Lap splits remain in the current session until reset. Closing or refreshing the page clears them.

दिसपट्टे

Time workouts and work sessions with a stopwatch, lap splits, pause and resume, or a countdown timer that runs locally in your browser.

Processed on your device

00:00:00.00

No. It runs in the current browser tab.