Shameless plug: I created an ST3 plugin called SynCycle[1]. It switches themes at sunrise and sunset. e.g. a light theme during daytime and dark theme during nighttime. For who's interested: you can install it with Package Control. [1]: https://github.com/smhg/sublime-suncycle
I use dark themes whenever I can, but I could be convinced to use a similar package that let me switch themes on command. You could even call the bright command Go Outside and the dark one Go Inside.