Answer: There are 24 hours in a day, four seasons, and four Jewish New Years on a shifting schedule. The same schedule exists between day and night: days are longer and nights shorter in the summer, and the reverse during the winter.
According to the Jewish calendar, an hour is not 60 minutes, each of which is 60 seconds, but a conventional unit. This unit is not constant but is time dependent.
According to the usual calendar, it is considered that there are 12 hours from sunset till sunrise and from sunrise till the next sunset is also 12 hours. But by light hours, 20 hours could lapse from sunrise until sunset, and night (darkness) would last only four hours.
In this case, the day hour and the night hour are absolutely different. It is a bit like the sundial, which does not have a uniform dial, but is on a logarithmic scale.
Since the length of the day and night changes every day, it means that the length of the night and day hours changes every day. They depend only on Partzuf Zeir Anpin in the world of Atzilut, which actuality manages these actions, because the upper light passing through it onto Malchut (and Malchut is us), defines everything.
If we could only know exactly how it operates, we would feel this system, a gigantic astronomical machine that surrounds us and thus affects us. We would then start getting closer to its internal parameters: what does it mean more light – less light, warmer – colder? If we would live and work according to such hours, it would have been a completely different life.
On the other hand, how is it possible to exist in these mechanics? Why do we need it? Why should it affect us in this way? If we would restructure and live in accordance with it, how would we feel nature and ourselves? It is interesting! This means that we would start to feel it in accordance with its influence on us. The surrounding world, space, stars, everything would shine differently.
From the Kabbalah Lesson in Russian, 12/30/18