Birkat Hachama - Overview

Overview

According to the Babylonian Talmud, the Sun makes a 28 year cycle to return to the position that it was in when the Universe was first created at the time (Tuesday evening) it was created.

According to Jewish tradition, the Sun was created on the fourth day (יום רביעי, yom rivi'i) of the week of Creation. Because Jewish law considers the time unit of a day to span from evening to evening, the beginning of the halachic fourth day, so to speak, is on Tuesday evening at sundown. The 28 year cycle therefore begins and ends at the point in time when the Sun was created, this being sundown on Tuesday. The Sun only returns to this exact position at sundown on a Tuesday once every 28 years.

Despite the rigorous calculations that follow, there is no synchronization of this prayer and the actual astronomical point in time when the sun crosses the celestial equator; the symbolism is no different than a situation in which the molad for Tishrei would fall out by day on a Sunday and Rosh Hashanah falls out on Monday.