Hi @gazo, welcome to the Sonos Community!

While you can’t do this with one alarm, you can do it with two. Alarms currently work on a weekly basis so you’ll need to make a second alarm if you want both a week A and week B schedule. Though, you will have to go into the alarms section in the Sonos app and disable the alarm you’re not using manually. 

I’ll also mark this thread as a feature request for alarms having more customization and forward it to the relevant teams for their consideration.

I hope this information helps!

thanks for considering this eveolution of the radio settings, it would be muche helpful to avoid switching manually alarms every week