Good question. On the Shabbat before the new Jewish month begins (except for the Shabbat before Rosh Hashana for mystical reasons), an announcement is made to the congregation to inform them when the new month (Rosh Chodesh) begins. Part of this brief ceremony is a beautiful prayer which includes many important requests — both physical and spiritual — that we turn to God to help provide us with in the coming month.
Aside from a Jewish month being a period of time and part of the year, it has a very special significance to the Jewish People in particular. Our Talmudic Sages teach us that we base our calendar on the lunar cycle because the Jewish People’s essence and experience throughout history is compared to the waxing and waning of the moon. As a nation and as individuals we go through periods of growth, happiness and peace, while at other times we face greater challenges and more difficult times. Yet, we are always confident that God will help us ultimately thrive, and even recognize the challenging times as opportunities for growth. The new month signals to us a new beginning (new moon), in a sense, followed by growth (the moon’s increasing), and the recognition of possible difficulties (the moon’s decreasing). Life may be a series of “ups and downs”, but we are assured that just as there is a “renewal” of the moon, so too we will be “renewed”.
The text of this prayer and blessing can be found in any Siddur, but for your convenience I will present it here in English.
“May it be Your will, God, our God and the God of our forefathers, that You inaugurate this month upon us for goodness and for blessing. May You give us long line – a life of peace, a life of goodness, a life of blessing, a life of sustenance, a life of physical health, a life in which there is fear of Heaven and fear of sin, a life in which there is no shame nor humiliation, a life of wealth and honor, a life in which we will have love of Torah and fear of Heaven, a life in which our heartfelt requests will be fulfilled for the Good. Amen, Selah.
May He Who performed miracles for our forefathers and redeemed them from slavery to freedom redeem us soon and gather our dispersed from the four corners of the earth, uniting all of Israel, and let us say Amen.
The new month [name of the month] will be on [day(s) of the week] which is (are) coming to us and all Israel for goodness.
May the Holy One, Blessed is He, renew it upon us and upon all His people, the family of Israel, for life and for peace, for joy and for gladness, for salvation and for consolation, and let us say: Amen."