Time of day animation concept idea!

I have come up with an idea for an animation that I would like to know if it is possible in flash. I am sure it is.

I basically am going to create three time of day states. Morning, Afternoon and Evening. The morning would have a morning sky illustration(animated in some way) the same for afternoon and evening states.

So in essence three swf’s maybe.

Is it possible to load a particular swf based on time of day, or better still change the sky gradient on a time interval, maybe gradually fade out the animated clouds and blend in night time stars somehow.

Can anyone shed some light on the subject please.

I would really like to know what is and what is not possible in my request.

Many thanks and I look forward for some replies.

Cheers

Trev