What is the Ruling of Salah Before its Time?

It must be known that performing prayer before it's time has started is not accepted, even if you only did the Takbeerat al-Ihraam (the opening takbeer) and then the time of prayer started immediately after the takbeer. So, it is not accepted as an obligatory prayer. That's because something that has a specified time for it is not valid before it's time, Just as, if a man wants to fast before Ramadhan even if it is by a day, it is not considered as a day from Ramadhan for him. Likewise, if he prayed or even if he said the Takbeerat al-Ihraam before the entering of the time, then indeed the prayer is not accepted from him as an obligatory prayer. However, if he was ignorant, he didn't know, it becomes a naafilah (voluntary prayer) and it becomes compulsory upon him to repeat the obligatory prayer