Rosh Chodesh which literally means "Head of the Month" is a monthly holiday that celebrates the arrival of the new moon, marking the start of a new month in the Jewish calendar.
The Jewish Calendar is a lunar calendar with twelve lunar months and 354 days per year. Each lunar month consists of 29 1/2 days. Since it is impossible to switch months in the middle of the day, certain Hebrew months have twenty-nine days whilst others have thirty days.
In order for the Jewish Festivals to be synchronized with the proper season, for example Passover (Pesach) which must fall in the spring (in Israel - the Northern Hemisphere), a leap year is added every few years. In a nineteen year cycle there will be seven leap years.
The Jewish leap year, however, is not like the leap year in the Gregorian calendar which is one day added on at the end of February every four years. A Jewish leap year adds on an entire month to close the gap between the 354 day lunar calendar and the 365 day solar calendar. Since the month of Adar (approximately February-March) is the last month of the Hebrew year, we add on an extra month at this time. We then have Adar I and Adar II which assures us that the holidays will be celebrated in the proper season. Originally, the date of Rosh Chodesh was confirmed on the testimony of witnesses observing the new moon, a procedure known as Kiddush Hachodesh (sanctification of the month). After the Sanhedrin (an assembly of either 23 or 71 elders or rabbi's, appointed to sit as a tribunal in every city in ancient Israel) declared Rosh Chodesh for either a full 30 day month or a 29 day month, news of it would then be communicated throughout Israel and the diaspora.
This system was dependent on the functioning of the Sanhedrin to declare the month, and to communicate this month to far-flung Jewish communities. In the 4th century CE, this became impossible and instead a fixed calendar of 29 and 30 day months was instituted by Hillel.
At the end of a 29 day month, Rosh Chodesh is celebrated for one day, on the first day of the new month. At the end of a 30 day month, Rosh Chodesh is celebrated for two days - the 30th day of the previous month, and the 1st day of the new month.
With the exception of the month of Heshvan, the eighth month of the year, every single month of the Jewish Calendar has some sort of special day or special observance. The importance of Rosh Chodesh is therefore obvious.
The names of the months are not Hebrew but Babylonian. The Bible refers to the Jewish holidays only by the order of the months and not by the Babylonian names which were assigned long after the canonization of the Torah. For example, the Torah gives the date of Yom Kippur as the tenth day of the seventh month, whilst the date of Pesach is the fifteenth day of the first month.
Tevet is the tenth month of the Jewish calendar when counted from Nissan and falls in the depth of winter in the Land of Israel. It usually consists of twenty-nine days, though in some years it may have thirty. Tevet arrives as the brightness of Chanukah fades, and the physical world grows colder and darker. This seasonal reality mirrors the spiritual character of the month, which is marked by concealment, restraint, and the quiet strength required to endure difficulty with faith and clarity.
The most significant observance of Tevet is the Fast of the Tenth of Tevet, which commemorates the day on which Nevuchadnezzar, king of Babylon, laid siege to Jerusalem. This event marked the beginning of the process that ultimately led to the destruction of the First Beit HaMikdash, as recorded in the Book of Kings. Unlike other fast days, this fast can fall on a Friday and is still observed until the onset of Shabbat, underscoring its severity. Chazal emphasize that this day represents not the destruction itself, but the moment when spiritual vulnerability first allowed it to begin. Later traditions also associate this period with the passing of Ezra the Scribe and with the translation of the Torah into Greek, events seen as diminishing the clarity and sanctity of Torah in the world. Tevet contains no Yom Tov, reinforcing its nature as a month of inner avodah rather than outward celebration.
In Kabbalistic thought, Tevet is a time when Divine light is deeply concealed. The Zohar teaches that light which is discovered through struggle is more enduring than light that is openly revealed. The darkness of Tevet is therefore not an absence, but a challenge — an invitation to develop inner resilience, faith, and discernment. The very heaviness of the month pushes a person inward, encouraging reflection and spiritual strengthening.
The zodiac sign associated with Tevet is Gedi, Capricorn, symbolized by the mountain goat. This image reflects persistence, patience, and steady ascent. Unlike signs associated with speed or openness, Gedi climbs slowly and deliberately, navigating difficult terrain step by step. This mirrors the spiritual work of Tevet, which is not about sudden inspiration, but about determination and consistency in the face of challenge. While Judaism teaches that mazal does not determine a person’s fate, Chazal explain that each month has a spiritual climate that influences the type of avodah most accessible at that time.
The tribe connected to Tevet is Dan. In the blessings of Yaakov, Dan is described as a judge of the people. The tribe of Dan was positioned at the rear of the Israelite encampment in the wilderness, tasked with protecting those who lagged behind and retrieving what was lost. This role reflects Tevet’s spiritual function: confronting areas of weakness, restoring what has fallen, and bringing order and justice into places of confusion or darkness. Dan’s strength lies not in prominence, but in quiet responsibility and moral clarity.
Tevet is associated with the precious stone known as Leshem, one of the stones set into the Choshen, the breastplate worn by the Kohen Gadol. Traditionally identified as lapis lazuli, this deep blue stone symbolizes hidden wisdom and depth. Its color evokes the night sky and the concealed layers of reality, reminding us that truth and holiness are often hidden beneath the surface and must be patiently uncovered.
According to Sefer Yetzirah, the Hebrew letter of Tevet is Ayin, meaning “eye.” This letter represents vision, perception, and the ability to see beyond appearances. In a month characterized by darkness and concealment, the avodah of Ayin is especially relevant: developing inner sight and recognizing the presence of Hashem even when it is not immediately apparent. Tevet calls for refined perception rather than external clarity.
The limb associated with Tevet is the liver, an organ connected in Chazal to raw energy and emotional intensity, particularly anger. The liver processes heaviness and transforms it into usable strength. Spiritually, this reflects the task of Tevet — to refine instinct and emotion, elevating them into disciplined and purposeful service of Hashem. It is a time to work on self-control, judgment, and inner balance.
An additional dimension of Tevet is its relationship to Chanukah. The month almost always begins while Chanukah candles are still being lit, symbolizing light entering darkness. As the candles fade, their message remains: even the smallest light, when kindled with intention, can endure in the deepest night. Tevet teaches that faith does not depend on constant illumination, but on the strength to continue even when light is hidden.
In essence, Tevet is a month of quiet endurance and inner growth. It does not offer the joy of festivals or the warmth of revealed spirituality, but it provides something deeper — the ability to stand firm in darkness, to judge wisely, and to uncover hidden light through patience and faith. In doing so, Tevet prepares the ground for renewal and revelation in the months that follow.