This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Regular Months gathers the twelve fixed months of the Hebrew calendar, the months that recur every year, as distinct from Adar II, the thirteenth month a leap year alone inserts.
The calendar carries two competing counts from its own opening months. Nisan is the first month of the religious year under the numbering Exodus itself sets out, though the seventh of the civil year; Tishrei is the seventh religious month but the first of the civil year, its name glossed as beginning to match that civil role, and this double numbering is unique to Tishrei among the twelve. Nisan carries Passover on its fifteenth and never doubles in a leap year, since it is Adar, six months earlier, that the calendar duplicates instead.
Festivals sit unevenly across the year. Tishrei is the busiest month by far, holding Rosh Hashanah, Yom Kippur, Sukkot and Simchat Torah in succession, while Cheshvan immediately after it is the one month with no festival or fast day at all, earning it the name Mar Cheshvan, bitter Cheshvan. Sivan holds only Shavuot, a single peak completing the Omer count begun in Iyar, and Elul carries no fixed festival, functioning instead as a preparatory month of self examination ahead of the New Year that follows it.
Mourning and joy each cluster rather than spread evenly: the seventeenth of Tammuz opens a three week mourning period running through Av's ninth day fast, Tisha B'Av, commemorating the destruction of both Temples, while Adar is remembered as the calendar's most festive stretch outside Tishrei. Several Babylonian derived names, Tammuz, Kislev, Tevet and Shevat among them, carry no settled native meaning the atlas can record, unlike the more transparently glossed Nisan or Elul.