סוֹד הָעִיבּוּר

ביטוי (אנגלית)

The Secret of Intercalation/ the science of fixing the calendar/ the science of intercalation

הגדרה (אנגלית)

The precise method for calculating leap years. The art of calculating the Hebrew calendar and the timing of the festivals, before the calendar was computerized (see also: "intercalation of the month").

("But below, the elders of Israel, who know the secret of intercalation, take from the day and give to the night, and take from the night and give to the day; and when they go out from the House of Assembly, after they have established the heads of months and the heads of years, intercalated the year, and fixed the appointed times, immediately throughout all the land their line went forth" — Midrash Tehillim (Buber), Psalm 19; and likewise: "And this is the aspect of the secret of intercalation, which is entrusted only to the great ones of the generation, who have great souls, for the motions of the spheres are through intellectual beings, which are the angels" — Rabbi Nachman of Breslov, Likutei Moharan, Torah 61, 3).