F1-11 works for me F12 does nothing.
F11 turns day to night and as time passes, if you hit F11 it set's (me) back to the time i loaded test mode.
If FPSCR is closed/reopen then (for me) it is reset to day time.
Now i wounder if this might be due to the FPS help box that appears when the default video card is not up to the task and clicking 'yes' disables F12?
Heck you have it good, I'm running a I3 sandybrige for a V-card.. yep-- ouch!
Looks like lee thought of 'Daylight savings time'
Having Fun with what you create,should be the only requirement.