Likutei Sichos, vol 32, Emor 1, Rabbi Chaim Wolosow
https://www.torahrecordings.com/likutei-sichos/032/012_001 The Rebbe explains why the Rambam arranges Sefer Zmanim differently than the Torah and Mishnah. The Torah highlights holy times; the Rambam highlights the Jew’s obligation. Through mitzvos, the festivals influence the whole year and even transform time itself.