Whey and Casein protein help!!!?

So i get the fact that i should take whey protein right after i work out, but how long after i take whey protein should i take casein protein? I'm most likely going to go with Optimum Gold Standard 100% Whey and Optimum Gold Standard 100% Casein. Are those good to take? I've heard whey after a work out and than casein before bed. Is this true?