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/sunset/sunrise. 

The script doesn't end until you stop it. 

There a three variables that you can change in each script file, I put them at the top. Lat & Long - Obviously latitude & Longitude. 

You can manually enter your own in the script file itself and the script will use those values. If they numbers are out of range (default), when you run the script it will try and determine them, it takes a few seconds to do this (actually it does Lat instantly but takes time with Long) and it doesn't get them exact but usually comes pretty close. The next important one is h, which is the angle the sun is to horizon.

Sunset & Sunrise default I use is h = -2, this seems to be the angle which the sun is fully below the horizon. The program is not 100% accurate so -2 will pretty much ensure the sun is always just below the horizon. 

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

For viewing what stars are visible Setting h = -10 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. 

These scripts only work on planet earth and you can't change location while the script is running (well you can, but the script won't update and use sunset/sunrise times at the original 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. 