[cantsingh]

You can use the Spotify Smart Playlists feature to do this. I used to do something similar before giving up. It's clunky, but it works. You basically set it to pull all new songs from the feeder playlists into the accumulation playlists, every night.

[unsafecast]

I can't find an official feature, you mean this?

http://smarterplaylists.playlistmachinery.com/