Hello,
Basically I have a game with a day/night cycle, and throughout the 24 hour period, different lights turn on/off throughout the map. My question is, would it be better to handle the light changes (enabling lights, moving them, changing part materials, etc.) on the server, or would it be better to handle it on the client?
If you are doing actions like tweens, I suggest you handle turning them on with the server. It will reduce lag on them and will make it so that the server has to do less resource-intensive tasks. The client should be able to do all of these to keep the load off of the server when it is time to change. Even if the load is minimal, the client should still be able to handle it for you.