Outdoor white balance based on... time of a day?

Well i just had a crazy idea for white balance in outdoor. As a sun is quite predictable, it should be possible to exactly predict a scene temperature outdoors at given time at given location on the earth without any clouds on sky. Probably clouds might affect this value by some small percentage, however I can't find any usefull information on the web about that idea. If anyone heard about that concept before and maybe got any calculator for that, please let me know! It sounds like an interesting idea of easily correcting white balance in post-processing.