Hi,

ich hab grad mal im Spotifyforum nach der Frage gesucht und das sagt ein Mitarbeiter dazu: 

Basically, we're releasing new music every day. When it's cleared for release, the uploading starts. It can be at different times. As it's quite technical, it can take a while and there isn't a specific release timeframe. But we're usually nice and quick.

This uploading is done on US time, so when it appears on Spotify very much depends on which country you're in.

Also haben die wohl keine bestimmte Zeit dafür :)