I'm not well-versed in physics, so I hope you'll forgive me if this question is significantly off the mark.

I'm interested in the predominant frequencies of light over the course of one day. My understanding is that as the sun rises and falls, the atmosphere absorbs differing amounts of light, and that is responsible for the changing colour of the daylight, for example becoming more red as the sun sets.

I guess that there is some curve from (all but) absolute darkness, through to broadband white light during the middle of the day, back to darkness again over the course of twenty-four hours?

If so, is it possible to approximate the makeup of the light at a given point during the day? And if so, how? I appreciate that there are probably significant complicating factors, so any rough approximation would be fine.

Again, I'm coming from a layman position here, so I apologise if I've drastically misunderstood something.