How do scheduled push notifications work if the phone restarts?

Platforms(Android/iOS/web/all): android, ios

I am about to start working on a kind of timer/ countdown app. The goal would be that you can set multiple timers and when they timer runs out you would get a notification.

Doing some research I see that I can’t easily run background processes with expo, so I thought that maybe it would make more sense to just schedule a notification x seconds into the future, as soon as the timer is created. Which I see if possible with this notifications API: Notifications - Expo Documentation

I’ve tested it out and it seems to work okay. But I’m planning to have the ability to create timers that can last up to a year of more. And I would definitely restart my phone multiple times. How would the application behave? Will I have to reschedule all notifications on phone restart? Will the api handle that for me automatically?

I would prefer this app to not require any internet connectivity to work properly, and I don’t plan on managing a server to schedule notifications.