Other mods out there like this, but this is a streamed replacement of time.xml that seems to be working well enough
The timescale stays vanilla but the sun and light patterns are smoother

The sunrise starts at 4am and finally rises at around 7am
The sunset starts at 6pm and sets at around 7pm
The sun appears more prominent throughout the day

All daytime lighting transition are drawn out and some cloud effects are amplified
Night/twilight is about 12 hours, with light fading sharply at dusk and dawn
Most of the night is now moonlight only

Version 1 so still room to improve

Drop my folder 'Improved Sunrise and Sunset' into the lml folder

Thanks,

-Bird