This information can be used for scheduling holiday music.  First, recall the overall UMix scheduling procedure:
- Select Playlists
 - Schedule Music
 - Program Music
 - Assign a Program to a Location
 
If you already have music playing, then you already have a Program assigned to your location(s).
To get some holiday music or specialty music playing for some brief period, all you'll need to do is:
- Select the playlist(s). 
 - Create a new schedule.
 - Add the schedule to the program you already have playing by editing that program.
 
It's that easy.  See screenshots below.
Select the Playlist
Add Schedule to the Program