It was said that sleeping during the day is of three types: good habit which entails sleeping around noon: careless habit, which entails in the early morning and keeps one busy from matters of this and the Next Life:and madness, which occurs after Asr(afternoon). This is why some of the salaf said " those who sleep after Asr and lose their minds should only blame their own selves"
taken from 'Healing with the Medicne of the Prophet" By Imam Ibn Qayyim Al -Jauziyah(English edition pg 215)