To do this:

1. Open the Clock app on your iOS device and tap the Timer tab at the bottom right of your screen.
2. Tap the When Timer Ends option, then select Stop Playing (at the bottom of the list). Tap Set.
3. Set the timer for when you want the SiriusXM App to stop playing, and then tap the Start button.

Your iOS device will stop playing audio from the SiriusXM App at the time you have set.