Spotify's playlists update frequency varies depending on the type of playlist.

1. Personalized playlists like "Discover Weekly" and "Release Radar" are updated regularly. "Discover Weekly" updates every Monday, providing you with new songs based on your listening habits. "Release Radar" is updated every Friday with new releases by artists you follow or listen to frequently.

2. "Daily Mix" playlists are updated every day. These playlists are created based on different genres you listen to and contain a mix of your favorite songs and some new recommendations.

3. Editorial playlists, curated by Spotify's team, don't have a set schedule for updates. The frequency of updates can depend on many factors like new releases, trending songs, or specific events.

4. Collaborative playlists, created by users, can be updated anytime by the users who have been granted access.

5. Your "Liked Songs" playlist updates every time you save a new track to it.

Remember to keep your Spotify application updated to the latest version to ensure you're getting all the new features and updates.