On Wednesday, April 8, 2009, the Jewish world celebrated not only Leil HaSeder, but also Birkhat HaChama (the Blessing of the Sun). This ritual is done every 28 years, to mark the return of the sun and the earth to their original alignment (time and day) as it was at Creation. The spring of Year 5769 marks the 206th completion of this solar cycle and the start of the 207th.

The Talmud in B’rachot 59b instructs one who sees the sun bitkufatah (“at the beginning of its cycle/at its turning point”) to make the b’racha “oseh (ma’aseh) bereishit,” the blessing said on observing wondrous natural phenomena. Abaye explains that this means “every 28 years…when t’kufat Nisan (the Spring equinox) falls on Tuesday evening/Wednesday,” which commemorates Day 4, when the sun and moon were created (Genesis 1:14-19). The word tekufah can refer to either the 3-month season or the first day of each season, which is either an equinox or a solstice.

Abaye’s calculation is based on the statement of Shmuel in Eruvin 56a that the solar year takes 365¼ days. Accordingly, every four years (4 x the 6-hour fraction) the alignment returns at the original time of day, but it takes seven such four-year periods (28 years) for it to return also to the original day of the week. For reasons related to calendar history, that date falls on April8 inthe 20th and 21st centuries (not March 22), and not necessarily on Pesach, which makes this year’s timing even more rare and special.

The recitation of the b’racha is done in the morning (in the “3 hour” period for reciting K’riat Shma [some say until midday]); a minyan is preferred but not necessary. Most require that the sun actually be visible. Over the years various ceremonies have developed around the b’racha. The Mishnah Berurah (Sh”O, Orach Hayyim 229:2) mentions Psalm 148, the b’racha “oseh ma’aseh bereishit,” the hymn El Adon from the Shabbat morning service, Psalm 19, Aleinu and Mourner’s Kaddish.

Unlike Kiddush Levana (the Sanctification of the Moon), which is tied to the moon’s actual position, Birkhat HaChama reflects the reality in the Biblical narrative, not the precise astronomical data. In many instances in Judaism, e.g., on Shabbat or under the huppah, we try to recall or even recreate a moment of Gan Eden, the way the world was on that first Shabbat. Every 28 years, we go even further back in time, to the moment the heavenly bodies were put in place. A rare moment indeed – save this piece for reuse, in 2037.