From Music Player Daemon Community Wiki

[edit] mpd_alarm.pl

This is a perl script and an associated configuration file. It is meant to be run in the background constantly. The script will start mpd playing at a configurable time. It will slowly increase the volume over time. It's designed to be used as an alarm clock. It re-reads the configuration file occasionally, so you can reset the time for the alarm to go off by changing th config file (without restarting the program).

It is available as a tarball here.