style change

I'm just wondering how to change the style (theme) of my forum without the approximately 120 active users noticing anything. There are many template and addon adjustments that I have to make after switching to a new style. This will probably take place over a few days. Now, what's the best...

With this addon forum style will be changing automatically depending on part of the day. So users that come at 13:24 will see "day style" and users that come at 02:51 will see "night style". It is useful because light styles with prevailing white color are very uncomfortable (physically) at...