Airtime is an open source application that provides remote and
collaborative automation of a broadcast radio station.

Major features:

• Web-based remote station management. Authorized personnel can add
  programme material, create playlists or smart blocks, and stream in live,
  all via a web interface.
• Automation. Airtime has a scheduler function that enables users to
  create shows with content for playback at the exact date and time specified.
• Playlists, smart blocks and remote stream URLs can be used multiple times.
• Solid playout. Airtime uses the open source Liquidsoap streaming language for reliable and precise playback to multiple outputs.
• Open, extensible architecture. Stations are free to extend and alter
  all parts of the program code, under the GNU AGPLv3 license.

www.sourcefabric.org/en/airtime
en.wikipedia.org/wiki/Airtime_(software)