misheyakir9Point5Degrees
This method returns misheyakir based on the position of the sun when it is 9.5˚ below geometric zenith (90).
Sources: This calculation is based on
Rabbi Dovid Kronglass's calculation of 45 minutes in Baltimore as mentioned in Divrei Chachamim No. 24
brought down by Rabbi Yechiel Avraham Zilber's Birur Halacha, Tinyana, Ch. 18.
This calculates to 9.5.
Also see Rabbi Yaakov Yitzchok Neiman in Kovetz Eitz Chaim Vol. 9, p. 202 that the Vya'an Yosef (Rebbe of Pupa - ZmanAuthority.GREENWALD) did not want to rely on times earlier than 45 minutes in New York.
This zman is also used in the calendars published by Rabbi Hershel Edelstein.
As mentioned in Yisroel Vehazmanim, Rabbi Edelstein who was given the 45 minute zman by Rabbi Avraham Yehoshua Bick.
The calendars published by the Edot Hamizrach communities also use this zman.
This also follows the opinion of Rabbi Shmuel Kamenetsky who provided the time of 36 and 45 minutes, but did not provide a degree-based time.
Since this zman depends on the level of light, Rabbi Yaakov Shakow presented these degree-based times to Rabbi Shmuel Kamenetsky who agreed to them.
Return
the Date of misheyakir. If the calculation can't be computed such as northern and southern locations even south of the Arctic Circle and north of the Antarctic Circle where the sun may not reach low enough below the horizon for this calculation, a null will be returned. See detailed explanation on top of the AstronomicalCalendar documentation.