With Centova v3 & SHOUTcast v2 server, you'll find 2 options for fade times under settings > auto dj.
The Crossfade length specifies how many seconds of the end of a track are blended into the beginning of the next track.
The Crossfade threshold specifies the minimum track length (in seconds) for which crossfading should be enabled. Tracks shorter than this length of time will not be crossfaded.