You can set f.lux to start dimming 10 hours before you wake up by selecting 'working late' from the dropdown menu in preferences and by setting the time in '7:0

You can set f.lux to start dimming 10 hours before you wake up by selecting 'working late' from the dropdown menu in preferences and by setting the time in '7:00 is when I wake up'. I think the option has been there since 2014. Very useful currently when the sun sets before 4 p.m. :)