You could arrange your daily music schedule into General Rotation playlists. Something like
00:00 - 06:00 Various
06:00 - 12:00 Morning music
12:00 - 14:00 The '80s
14:00 - 00:00 The '90s
But make sure to also have one General Rotation set for the entire day, as a fallback, otherwise Centova Cast will ignore the time restrictions on your other playlists. So have one like:
00:00 - 00:00 Fallback
It could even be composed from a single track which contains like a second of silence, or from a bunch of tracks that you don't mind if they rarely play during the day. Set this playlist to have the lowest weight (1), as tracks from this playlists will still pop from time to time. With a low weight this will happen very rarely.