Harman Kardon CITATION OASIS - Playback and Features; DAB Radio Operation

Set the sleep timer for music playback
Desired Action
Voice Command
(Say “Hey Google”, then...)
Set a sleep timer during music playback “Set a sleep timer for 30 minutes” / “Set a sleep timer at 9:30”
Set a sleep timer before music playback ”Play some music for 30 minutes”
Note:
The Sleep timer function is now available for Chromecast built-in and Bluetooth music streaming. For FM, AUX and AirPlay music streaming, this feature may be
available in the future via automatic software updates.