Shortly before sundown on the 29th of Adar, G-d commanded Moses regarding the mitzvah of sanctifying the crescent new moon and establishing a lunar calendar. This is the first mitzvah the Jews were given as a nation.
Moses had difficulty envisaging the moon's appearance at the exact moment of its monthly rebirth. After the sun set, G-d showed Moses the crescent new moon of the new month of Nissan, showing him the precise dimensions of the moon at the moment the new month is to be consecrated.
For the generations that followed, each new month was ushered in when two witnesses testified before the Sanhedrin (rabbinic supreme court) that they had seen the molad, the new moon. In the 4th century CE, Hillel II foresaw that the Jews would no longer be able to follow a Sanhedrin-based calendar. So Hillel and his rabbinical court established the perpetual calendar which is followed today -- until Moshiach will come and reestablish the Sanhedrin.
Links::
Lunar Time
Rosh Chodesh
The Molad
A few months after its creation, Napoleon's "Sanhedrin" (rabbinical supreme court) was dissolved. The Sanhedrin was created to approve certain religious regulations requested by the French "Assembly of Notables." The regulations were designed to blur the distinction between Jews and non-Jews.
The rulings of this pseudo-Sanhedrin were never adopted by Jewish communities.
Link:: Napoleon Bonoparte
Some people think that if they were truly spiritual, they would never eat.
In truth, few acts are as divine as eating food.
Eating is similar to sifting gold. You grasp the divine spark within a food and reject the dross. And then, in the mitzvahs energized by that food, you carry that divine spark back to its origin within the oneness of its Creator.
That is why there are foods that are forbidden and foods that are permissible. The Hebrew word for “forbidden” is assur—meaning tied down. “Permissible” is mutar—untied.
Kosher means “fit.” Foods that are assur are not fit for the divine act of eating because the divine spark within them is tied down and cannot be released. If we would eat them, rather than carrying that spark upward, we would be pulled down with it.
But foods that are mutar are fit and ready to release powerful divine energy into all the mitzvahs we do.