is
Returns true if the current day is Yom Kippur Katan. Returns false for Erev Rosh Hashana, Erev Rosh Chodesh Cheshvan, Teves and Iyyar. If Erev Rosh Chodesh occurs on a Friday or Shabbos, Yom Kippur Katan is moved back to Thursday.
Return
true if the current day is Erev Rosh Chodesh. Returns false for Erev Rosh Hashana.