All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
We ask Allah to reward you for your adherence to Islam and we ask Allah to give you guidance, help and luck. Know dear brother that the person should fulfill the duties that are incumbent upon him. But he should not fulfill any duty at the expense of another duty. Salman al-Faarisi said: Your body has a right upon you, your soul has a right upon you, your wife has a right upon you and your guest has a right upon you. When this saying was reported to the Prophet he said: Salman was right. Salman was right. It is important to realize that seeking Halal livelihood is a form of worship which is rewarded. Moreover, providing one's family with expenditure, education, …etc. is a form of worship which is rewarded too. Seeking knowledge and other supererogatory acts are all forms of worship. The above facts prove that all the life of the person is for Allah. Allah Says (interpretation of meaning): {Say: truly, my prayer and my service of sacrifice, my life and my death, are (all) for Allah, the Cherisher of the worlds: No partner hath He: this am I commanded, and I am the first of those who bow to his will.} [Quran 6:162-163]. So, you do not need to specify a given number of hours for every obligatory act, instead you should give each right the amount of time needed for performing it in the best way. Besides, what you do in these three hours is a good deed. But if you can increase the time, it will be better provided this will not cause a neglect of any obligatory act. On the other hand, we advise you to vary the deeds you perform to avoid getting bored. You can, for instance, pray for some time, recite some Qur'an in other times, read in the books of Shariah, listen to cassettes of admonition, visit scholars and pious people, visit Da'wah centers and participate in their Da'wah activities, …etc. As for the daily program of the Prophet or that of Caliph Abu Bakr they did not have any permanent daily program. Their program used to change according to situations, rights and duties. In fact, the Prophet used to perform the Ibadat, lead the Ghazwat, do the visits and satisfy the different and numerous needs of the Muslims. For more details about this subject, you could read the books dealing with the biography of the Prophet like the good and concise book ‘the Sealed Nectar’. By the way, there is a good English translation of this book. Finally, here is a suggestion of a daily program:
1) Waking up a little bit before Fajr prayer to pray Witr and supplicate Allah. 2) Praying Fajr in congregation in the mosque. Sitting in the same place where you prayed performing the morning Adhkar (supplications) and reciting Qur'an until after the sun rises, then performing the 2 Ishraq Rak'ahs as well as Dhuha. 3) Having breakfast then going to work and praying Zuhr. 4) After Zuhr, have a rest, and then pray Asr. 5) After Asr, you can carry out the program you mentioned until after Maghrib. 6) After Isha, spend some time with your family, do any homework you have and finally go to bed.
Allah knows best.