When a Jew calculates time according to the Jewish calendar, he intensifies his spiritual awareness. The principles by which Jewish time is determined are called "the secret of the ibur." The word "ibur" represents the insertion of an extra month every few years, but its literal meaning is "pregnancy," a leap year being a "pregnant" year, "meubar" in Hebrew.
Living according to the Jewish calendar imbues the mind with higher states of Jewish consciousness. The word "ibur" is related to the word "ivri," which means "Hebrew." (In Kabbalistic terminology, "pregnancy" symbolizes the development of an intellectual concept in a person's mind: initially, the intellectual concept exists at the level of "Chokhmah" (wisdom), which is a summarized basic point; it is then introduced into the "womb" of "Binah" (understanding), where it is developed in every detail and depth, becoming a mental structure, a complete concept. From this "pregnancy"—that is, from the development of an essential idea (Chokhmah) into its details (Binah)—the emotions corresponding to the developed idea subsequently arise.)