Does setTimeout and setInterval work in the background on iOS and Android when the screen is locked?

[acarlstein]

Will you help me? I'm trying to build two applications.

One application requires to create a series of timers.
The other application requires communication with a server to exchange coordinates.

Both applications must work when the app goes in the background, when the user locks the screen, or when the screen goes black.

Could someone please confirm whether setTimeout and setInterval work in the background for iOS and Android?

I'm aware that android might required a permission to do so.
I'm aware that iOS requires adding keys/values in the Info. list to do so.

If they do but require extra work, could a link to a tutorial be included? Thank you