Csar,
Consider the following letter the Rambam wrote to a friend which illustrates his work schedule. This was written 4 years prior to his death.
[Remember: his brother died at sea.]
I live in Fostat, and the Sultan lives Cairo. The distance between them is 4000 cubits [a mile and a half]
I get off of my donkey, wash my hands, and go out into the hall to see them. I apologize and ask that they should be kind enough to give me a few minutes to eat. That is the only meal I take in twenty-four hours. Then I go out to heal them, write them prescriptions and instructions for treating their problems.
Because of all this, no Jew can come and speak with me in wisdom or have a private audience with me because I have no time, except on Shabbat. On Shabbat, the whole congregation, or at least the majority of it, comes to my house after morning services, and I instruct the members of the community as to what they should do during the entire week. We learn together in a weak fashion until the afternoon. Then they all go home. Some of them come back and I teach more deeply between the afternoon and evening prayers.
Copy over the teshuva [written Torah response] I wrote to you and discuss it with all the scholars in your town. If, after that, you still want to come, I would happy to see you, but you should know you will not be able to learn with me here. My time is so compressed.
May your happiness, my dear pupil, increase and grow great, and may salvation be granted to our afflicted people.[1]
I know links are not allowed, feel free to google the text.