Nobody knew the day or the hour in which the new moon would be sighted in Israel until a couple hours ago.
The new moon is sighted every month to signify the start of a new month but this month, the sighting begins a two-day holiday called Yom Teruah, the Feast of Trumpets, or Day of Shouting. The start of this Appointed Time was expected as early as Monday evening, but the physical sighting of the crescent did not happen until 6:40 p.m. or so. That is when the live feed manifested the first shofar blasts in Jerusalem as I heard them here.
There are hundreds of factions of Hebrew faiths and calendars to choose from. Since all of the other holidays during the year depend on this one, it is important to know which is the most accurate. The people in Israel who follow the rules of Yom Teruah will not work during this Feast which seems to have started about two hours ago.
Where I live, sunset will come in about five hours and because it has been raining non-stop here, there is little chance that the new moon will be sighted here this evening. I could begin the Sabbat rest when the sun sets here, or when the new moon is sighted in however many days, or when the Temple Rabbi pronounces the beginning of Yom Teruah. Then again many temple officials pronounce Rosh haShana based on the computer models showing when the Moon received its first reflected light.
I always take the week off and celebrate the holiday for as long as it lasts across all beliefs. My Shabbat rest began on Monday evening and was proved to be false by the actaul sighting of the moon in Israel just now, and will end forty-eight hours after I see the new moon. All bases covered.
Why would I care?
Many prophecies foretell of the coming of Meshiach "at the last trump"
That last trumpet is called Tekiah Gadola, which is the exact time of that event. No man knows the day or the hour. But it will happen in the twinkling of an eye...
The Last Trumpet, "Tekia Gadola"- what every single Jewish person instantly understood, the 100th blast of the trumpet at Feast of Trumpets/ Rosh Hashanah. 6. Thief in the Night - a well-known documented Hebrew idiom, for the Captain of the Temple Guard - who came through the temple at night to see if any of the guards were asleep.ref.
The above text is just one of many pulled from a search string containing Tekia Gadola and Meshiach. I usually spend these days reading about all of the coincidental meanings and references to this day. What will you do for the last forty-eight hours before you see the Creator?
Final note: We only know the day or the hour for this year. If it does not happen this year, then we go back to not knowing...