If you have set alarm for 3 hours and 60 minutes, you can be 100% sure that alarm will ring at 3 hours and 60 minutes. You can trust us completely.
The alarm will still ring at 3 hours and 60 minutes, even if you refresh the browser, since we store the information in browser's local cache.
It will be gone. The alarm will not ring at 3 hours and 60 minutes, if you close the tab.
It will be gone. The alarm will not ring at 3 hours and 60 minutes, if you close the browser.