Run the script and whenever you switch to a new day (day, week, month & year) by pressing either -= [ ] or manually changing date it will automatically go right to the dawn/dusk/solar noon/sunset/sunrise. 

The script doesn't end until you stop it. 


Sunset & Sunrise default I use is h = -2, this seems to be the angle which the sun is fully below the horizon counting for atmospheric refractive. 

Negative the sun is below the horizon, positive it is above. 

For viewing what stars are visible Setting h = -18 is probably the best so I made a dawn to dawn and dusk to dusk because it's the time everything gets dark enough and you can still see a little big of dusk.

Noon to Noon is solar noon at your location 

 If you hold down the = or - or [ or ] keys while the script is running it will be a slightly slower and choppier than when you do it normally but it's not too bad. 