After all of the torah written on Birkat HaChama and reading some of the items on your wonderful site, I still am unclear on the following and would appreciate your assistance.
The equinox today is considered to be March 21.
The Birkat HaChama was April 8th.
This difference I saw explained was that the March 25th equinox of the Roman calendar was used and if this is then moved forward, using the difference in Shmuel's calculations which add up to 1 day every 128 years, if starting from when Shmuel lived (appx. 200 CE) this gets to April 8th.
If so, Shmuel relied on the March 25th date. Is this based on a slighly different definition of the equinox or simply following the calendar at the time.
The Rambam describes the definition as the rising of mazel Tleh. Does this have any connection to the modern day definition of the equinox or are we dealing with 2 different definitions?
Thank you so much !
Simcha Miller, Jerusalem
Reb Simcha,
(a) Since calendars are arbitrary, Julius' astronomers could have chosen any date for the equinox. Historians presume he chose 25 March (although we cannot even be sure of that - see attached excerpt from Reb Sender Epstein's article, footnote #27).
(b) The equinox is when the sun crosses the equator in its N/S path around the Earth (or when the equator faces the sun in the inclined Earth's circuit around the sun). That used to occur in Mazal Tleh at one point, but it has shifted due to precession (i.e. the inclination of the Earth changes over time).
Best wishes,
Mordecai Kornfeld