I had an idea when I saw that my university classmates who used my online schedule site were not always up to date when the schedule changed.

The idea is that I want to send a push up notification locally with a service worker who will check if the schedule has been modified and that at regular intervals.

I have two concerns.

1_ how to set up a regular check of the database (eg: every 15 min).

2_ is it possible to use Ajax with the service worker while the the browser are close.

And all this without a vaped key and without using the server except to check the database.

Thanks for your help