Timeline - Change keyframes dynamically?

Hi,

I´m using a timeline to control the amount of clouds in the skysphere. For example at 8am there a only a few clouds and at 1pm there are more and in the evening a lot. This works well, but I was wondering if there is a possibility to set timeline keyframes dynamically. So instead of saying from 8am to 1pm, I could use a random float range.Something like a “set keyframe array” would be great (time and value).

I guess that is not possible or am I wrong?

Thanks,
Michael