First day--New Moon

[YHVHSFOOL]

I have noticed there are two basic calanders that are follwed by believing followers. Rabinical, and Barley. I noticed in studying for the Day of atonement that there are two festivals held on the 15th of the month. Passover and Tabernacles.
Why do the calanders Start counting a day or two after the New Moon when says to sound the shofar on the New Moon and count that as day one? It put the Day of Atomement Yesterday instead of today or tommorow. In Ps 81 it says sound the shofar on the New moon and celebrate the feast on the full moon. These two feasts will only fall on the full moon if the shofar is blown on the New Moon. Or have I missed the understanding?
One recuperating from a day of affliction.....

[Nachshon]

On the New Moon is when the sliver of the moon is sited. This is how those of us who use the Aviv (barley) callendar do it. The Rabbinic callendar is just a precalculated callendar. It's not actually based directly on the cycles of the moon and seasons at this point. But the Talmud does record that it was based on the cycle of the seasons in the past. Hypothetically, it will be again one day.
I guess I don't understand your question.

A jester out of work is nobody's fool.

Shalom,
Nachshon

[Mark]

The new moon is the first sliver of a moon that can be seen in the night sky and is considered the beginning of months. In Oregon, that's not so easy being as we only see the moon about four months out of the year. Like most rabbinical processes, this became a meticulous process where witnesses must agree that the moon had been born.

The establishment of Rosh Kodesh (the New Moon) was never understood to be so simple as any ol' farmer looking up into the sky and saying, "Yup, there it is." The Sanhedrin would light a huge bon fire which ould be repeated on mountain tops all of the way from Jerusalem to Babylon so that everyone would know when the starting of the month would take place. There became a disagreement between differing sects as to when the New Moon should start and factions began lighting their own bon fires and this process was abandoned. The announcing the birth of the moon was then sent by official messenger.

While the Sabhedrin presided over Jerusalem, there was no set calendar. There was simply the establishment of the New Moon and everyone knew which month would be next in the cycle. Because the lunar cycle does not equally divide into the four seasons, the Sanhedrin would periodically declare a leap year (and throw another month in there). This would be done based primarily on two factors, if the Passover fell before or after the Spring equinox and also when the barley harvest ripened.

All of these decisions were made on the authority of the Sanhedrin. Then there came a problem. In the fourth Century, the Sanhedrin was disbanded. The reigning high priest, Hillel 2, saw this coming and created a perpetual calendar which is followed today. Just like in earlier times, this calendar is not universally agreed upon. Some believe that establishing the New Moon is as simple as looking into the night sky- if that were the case, it is difficult to understand why even in the earliest times there was such division on the subject. The process for identifying the start of the month is not specifically defined in the text of so it comes to deciding which rabbinical authority you choose to believe.

[YHVHSFOOL]

With Satallites, Mathmatic equations, and all the other strategies is there not some way for us to get our calanders squared. It just seems odd to me that secular calendars are able to know which night the Mew Moon is, but Jewish ones don't.
Thank-you for the explaination.

If the whole world be wise make me a fool.