Hi,
Here's one way.
In Automator, create a Calendar Alarm. This will have two actions from the Music library.
The first will be "Get Specified iTunes items". Click the Add... button in the action pane and specify your playlist.
The second action will be "Play iTunes playlist". You don't need to modify this, just make sure it's second in the workflow.
Save and close this Calendar Alarm, calling it something like "Play my Playlist". Calendar will activate and will create a new calendar called "Automator" if it doesn't already exist.
In Calendar, schedule this Alarm for every day at waking-up time.
Go back to Automator and create a second Calendar Alarm. This will have a single action, "Run AppleScript" from the Utilities library. Delete all the text in the action ("On run... yadda yadda... End run"). Type in a single line:
tell application "iTunes" to quit
Save this Alarm, calling it something like "Stop iTunes", and again you'll be taken to Calendar. Schedule the Stop iTunes alarm daily to run an hour after the first alarm.
Hope this helps,
H