This means, that we have to build a life around our meditation schedule, which I do not mind. If we sleep from 11 o'clock to 3 o'clock, will we get enough rest? Did the masters advice on that, how much to sleep? I will try it for a week, should I sleep at midday also, if I feel tired?

Meditation hours: 9-11 p.m, and 3-5 a.m. with small breaks, because I am not that skilled yet. Thank you instructor Almustafa.

Don't go overboard, but train yourself so that, gradually, you have the stamina to work like a master or prophet. Most people don't begin at that level, but gain it through years of work.

Yes, I will try. Now that the meditation time is getting close, I feel excited, interesting.

What are the factors that determine those two time phases 10pm and 4am? Do they change according to the varying times for sunset and sunrise throughout the year?

People living further away from the equator experience long days and short nights in summer and vice versa during winter. Does this have effects on transmutation and meditation?

These times are not determined by the clock or our latitude on the planet. They are generalities that indicate when to look for peaceful moments for meditation. Simply observe nature: usually at those times (10 and 4), the environment is at peace, thus it is easier for us to be at peace, too. Your own circumstances might be different. or you might not even own a clock, but that does not matter. The exact time does not matter.