Possible Duplicate:
Davening Shacharis?
When is the earliest time one can pray (the Shemone Esre) in the morning?
Reciting Keriath Shema' has its own rules, and I understand you may need to recite it again later, and you may need to don Tefillin and Tallith later as well.
But what is the earliest time one can fulfill one's obligation to pray in the morning, and according to whom? I'm trying to break this down to its simplest elements, so forgive me if it's not really that simple of a question.
