Yom Teruah means "Day of Trumpet Blowing." This is the meat of an e-mail I received from Israel concerning sighting the new moon for the Feast of Trumpets: it helps to understand how these things are figured:
"On Tuesday September 30, 2008 the new moon was not sighted by observers from Israel. With the time between sunset and moonset only 20 minutes this was exactly as expected. As a result, Yom Teruah will begin Wednesday night, Oct 1, which is the 31st day from the previous sighting. This is because a lunar month can only be 29 or 30 days long and the non-sighting tonight made the Sixth biblical month 30 days."
Happy Yom Teruah, beginning tonight! Love, Christine