Android Question Converting from Tasker

Hi, I'm new to Basic4Android, but I have experience of Visual Basic Programing. Some time ago I wrote an App in Tasker, which allows me to mute the phone (all sounds) for 30/60/90/120 minutes, by pressing the appropriate button, after which time the phone is unmuted.

I want to re-create this app, to teach myself Basic4Android, but I'm having a problem getting my head around the timing aspect of it and the muting. Any help would be welcome

Thanks