There is a lot of exposure and colour change between these 2 scenarios but my question is how to set my interval correctly.
Because when shooting the sun set 1/200 of a second would work just fine but as image gets darker I am going to decrease my shutter speed but what about my INTERVAL? Should I just leave it or do I need to interrupt my timelapse sequence to make some changes?

Thanks,

I normally use the same interval for the whole sequence, mostly 20 Secs or so - because changing the interval will accelerate the video.