sof
This method returns the latest zman tfila (time to recite shema in the morning) that is 4 * *shaos zmaniyos* solar hours after sunrise or sea level sunrise (depending on the isUseElevation setting), according to the GRA. The day is calculated from sea level sunrise to sea level or sunrise to sunset (depending on the isUseElevation setting).
Return
the Date of the latest zman tfilah. If the calculation can't be computed such as in the Arctic Circle where there is at least one day a year where the sun does not rise, and one where it does not set, a null will be returned. See detailed explanation on top of the AstronomicalCalendar documentation.