I'm a genuine late sleeper. Since my senior school years (it's ~ 12 years now, wow!) I've been studying / working "shifted hours". Most of this time I've been normally coming to school / university / work by noon. And even in my childhood, can't remember if I ever liked the idea of waking up / going to bed early. My creative powers come to their peak in the evening, while squeezing a fresh idea in the morning is murder.
Meanwhile, I often meet people who -- conciously or not -- judge that one must be an early riser to work truly well. Even in the creative sphere of IT this stereotype is popular. Is there any sane psychological ground for it? Or maybe it's just legacy of those times when people had to wake up early to do all the job during daylight?