is
Returns true if tomorrow is Shabbos or Yom Tov. This will return true on Erev Shabbos, Erev Yom Tov, the first day of Rosh Hashana and erev the first days of Yom Tov out of Israel. It is identical to calling hasCandleLighting.
Return
will return if the next day is Shabbos or Yom Tov.