During the Second Temple Era (circa 230 BCE), Cheshvan 7 was the date on which the Jew most distant from the Holy Temple -- who resided on the banks of the Euphrates River, a 15-day journey's distance from Jerusalem -- arrived at his homestead upon returning from the Sukkot pilgrimage. All Jews would wait for this before beginning to pray for rain. Cheshvan 7 thus marked the return to everyday activities following the spirituality of the festival-rich month of Tishrei.

Link: The Last Jew

Passing of Rabbi Meir Shapiro of Lublin, founder of the daily "page a day" regimen of Talmudic study known as Daf Yomi.

In the Land of Israel, prayers for rain (i.e., adding the words v'ten tal u'matar to the appropriate blessing in the Amidah prayer) commence on Cheshvan 7 (see "Today in Jewish History" above. Outside of the Holy Land, the date for the rain prayer is determined by the local needs. In the U.S., Europe, Russia and other northern countries, it is recited beginning on the 60th day after the autumnal equinox -- on December 4th or 5th.)

Once a month, as the moon waxes in the sky, we recite a special blessing called Kiddush Levanah, "the sanctification of the moon," praising the Creator for His wondrous work we call astronomy.

Kiddush Levanah is recited after nightfall, usually on Saturday night. The blessing is concluded with songs and dancing, because our nation is likened to the moon—as it waxes and wanes, so have we throughout history. When we bless the moon, we renew our trust that very soon, the light of G‑d's presence will fill all the earth and our people will be redeemed from exile.

Though Kiddush Levanah can be recited as early as three days after the moon's rebirth, the kabbalah tells us it is best to wait a full week, till the seventh of the month. Once 15 days have passed, the moon begins to wane once more and the season for saying the blessing has passed.

Links:

Brief Guide to Kiddush Levanah: Thank G‑d for the Moon!
More articles on Kiddush Levanah from our knowledgebase.