Is it permissible for a person to perform Isha' (Night) Prayer before its due time
because he works in a lab and should sleep before the time of `Isha' (Night) Prayer to rest and get up before the time of Fajr (Dawn) Prayer to go to work. Is it permissible for him to perform the Fajr (Dawn) Prayer and its two supererogatory Rak`ahs before their due times and before leaving his home because if he goes out, he will not be able to perform Salah on his way or during work?
It is not permissible for a Muslim to perform `Isha' (Night) Prayer before its due time to sleep early, rest, wake up before dawn and get ready to work early in the morning. His need to sleep early to rest in order to go to work early is not an excuse to perform `Isha' before its due time. It is also not permissible for him to perform the Fajr (Dawn) Prayer or its two supererogatory Rak`ahs before their due time. Whoever performs them before Dawn, their Salah is invalid and they should perform it again according to the Ijma` (consensus) of Muslim scholars. (Part No. 6; Page No. 150) It is permissible for them to perform the two supererogatory Rak`ahs of the Fajr (Dawn) Prayer before praying the prescribed Salah. Regarding what was mentioned that he cannot perform them at work, it is not a legal excuse to permit performing them or one of them before their due times. A Muslim should perform the five daily prayers in their due time even if some worldly actions are missed.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.