The optimal length/time for a nap

We've all been there. You lay down for a quick power nap at 2pm on a Sunday and before you know it, you wake up it's hours later, dark out, and you're incredibly disoriented. Sometimes, you don't even know what year it is!

My friends and I got into this debate... what is the best nap situation? How long and what time? For me, 30-45 minutes is best. And the sun can NOT set during that time frame. Going to sleep when it's light out and waking up when it is NOT light out is the ultimate mind F and will throw you off for the rest of the day. Any longer than 45 minutes, you're just too drowsy and that too will ruin your day. You also can't take a nap too close to bed time, because why not just go to bed then?