Changes the parameters of the solar cycle: Make days longer or shorter and control what portion of the cycle is night. Make nights darker if you like. Includes an optional Sun Never Rises mode.
+1
I love this mod. I use a 4x factor with 85% darkness.
Also, if would be fine if the new version only affected Nauvis, at least for an initial release.
I'm working on my own inspired version here Diurnal Dynamics. It's not feature complete by any means but it does give the basics plus some Space Age extras. Day length and accumulator capacity multipliers plus darkness config.