six hours later on this chart, or on Thursday at the sixth hour, Jupiter. Each year this will shift another day and six hours. It will take 28 years for Tekufat Nissan to return to being on Wednesday at twilight. It is worth noting that the true spring equinox occurs on March 21 yet Birkat Hachama is said 18 days later. This inaccuracy accrued over thousands of years as a result of using the inexact calculation of Samuel for the length of the year. Order of the service The service generally includes: Psalms 148:1–6 The blessing: "Baruch Atah A-donai E-loheinu Melech Ha`olam Oseh Ma`aseh Breisheet." Those who say the Shehecheyanu blessing, do so here. Psalm 19 Psalm 121 Psalm 150 A passage from the Talmud regarding the obligation of Birkat Hachama. Psalm 67 Aleinu The mourner's Kaddish. The Shehecheyanu blessing is not recited. There is no obligation to say Birkat Hachama: it is an opportunistic blessing recited only if one happens to see the sun in this state; such blessings (another example is the annual blessing upon seeing flowering fruit trees in Nisan) receive no Shehecheyanu. Those who do recite Shehecheyanu should take care to wear a new garment or have a new fruit close by, to remove all doubt. Occurrences of Birkat Hachama Occurrences in the last 120 years: Wednesday, 7 April 1897 (5 Nisan 5657) Wednesday, 8 April 1925 (14 Nisan 5685 – Erev Pesach/Passover Eve) Wednesday, 8 April 1953 (23 Nisan 5713) Wednesday, 8 April 1981 (4 Nisan 5741) Wednesday, 8 April 2009 (14 Nisan 5769 – Erev Pesach/Passover Eve)Birkat Hachama will occur next on Wednesday, 8 April 2037 (23 Nisan 5797) Wednesday, 8 April 2065 (2 Nisan 5825) Wednesday, 8 April 2093 (12 Nisan 5853) Wednesday, 9 April 2121 (21 Nisan 5881 – Shvi'i Shel Pesach/Seventh Day of Passover) Wednesday, 9 April 2149 (2 Nisan 5909) Note: Because the dates for Birkat Hachama assume a 365.25-day solar year and the Julian calendar also assumes a 365.25-day solar year, Birkat Hachama will always fall on March 26 in the Julian calendar. While Birkat Hachama usually occurs in the Jewish lunar month of Nissan, this is not always the case; it will occur on 29 Adar II (April 10) in the year 2233. Lerman's thesis Moshe Lerman suggested a background to Birkat Hachama by pointing out a possible connection between the traditional Hebrew dating and the two machzorim