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.
Kislev is the ninth month of the biblical Hebrew calendar and generally has 30 days, though in leap years the length can vary depending on the year’s calendar structure. In 2025, Kislev begins at sundown on 21 November 2025 and continues until sundown on 19 December 2025. Kislev falls in late autumn and early winter (in the northern hemisphere), a period when the days grow shorter and the nights longer. Despite the shortening of days, Kislev is often referred to as a month of light, hope, and spiritual revelation, balancing the natural darkness with an inner illumination.
The most widely known event of Kislev is Chanukah, which begins on 25 Kislev and continues for eight days. Chanukah celebrates the rededication of the Holy Temple in Jerusalem after the victory of the Maccabees over the Greek-Syrian oppressors. The miracle of the menorah, where one day’s worth of oil burned for eight days, represents divine providence, spiritual endurance, and the triumph of light over darkness. The themes of Chanukah resonate deeply with Kislev’s spiritual tone: even in a season of cold and gloom, the soul can kindle light and reveal hidden holiness.
Beyond Chanukah, Kislev is associated with preparation, planning, and spiritual readiness. It is considered a month when the seeds of blessings for the coming year are planted in the spiritual realm, aligning with the natural cycles of winter sowing and storage. Traditional sources describe Kislev as a time of joy, hope, and faith, which helps counteract the natural melancholy of the season.
Kislev is linked to the zodiac sign of Sagittarius, known in Hebrew as Keshet, meaning “bow.” This symbol reflects vision, focus, and the ability to aim for distant spiritual goals. Just as an archer pulls back the bow to launch an arrow, Kislev invites the soul to prepare, gather strength, and aim for higher spiritual achievements. The energy of Sagittarius is expansive, optimistic, and future-oriented, emphasizing faith and trust in the unseen. Spiritually, Kislev is a month of hope, encouraging the believer to reach beyond the immediate difficulties and trust in divine guidance.
The Tribe of Issachar is associated with Kislev. Issachar was known for wisdom, learning, and the study of Torah. The tribe’s traditional role was that of the scholar and the observer, understanding the cycles of time, work, and rest. In Kislev, this energy encourages reflection, learning, and insight. Just as Issachar understood the rhythms of the agricultural and spiritual year, Kislev invites attention to timing, preparation, and discernment. It is a time to study, plan, and build spiritual foundations that will bear fruit throughout the year.
Kislev is also connected to the precious stone of the Tribe of Issachar, the topaz. The warm, radiant colors of the topaz symbolize spiritual clarity, inner light, and steadfastness. Topaz reflects the qualities of optimism and hope, reinforcing Kislev’s theme of spiritual illumination amidst the darkness of winter. This stone serves as a reminder that even in difficult or obscure times, light and understanding are always available to the prepared heart.
The Hebrew letter associated with Kislev is כ (Kaf), symbolizing the “palm” or “spoon.” Kaf represents potential, receptivity, and the ability to contain blessings. Like a palm that holds and protects, Kislev is a month of spiritual receptivity: it is a time to gather insight, lessons, and blessings for the future. The month asks the individual to open their inner hand, receive guidance, and prepare to transform potential into action.
Kislev is connected to the kidneys, which in mystical thought are organs of judgment and discernment. The kidneys are linked to the ability to separate and filter, much like the spiritual task of Kislev: distinguishing between what is essential and what is superficial. Just as the kidneys purify the body, Kislev purifies the soul, helping the believer discern meaningful spiritual insights from distractions or illusions.
Etymologically, the name Kislev is thought to derive from Akkadian words meaning “to trust” or “hope,” which mirrors the general tone of the month. It is a period when faith in divine providence is particularly emphasized. Kislev sits between the harvest season of Cheshvan and the deeper winter months of Tevet, symbolically bridging the abundance of material blessings with the inner work of spiritual refinement. The festivals, mystical correspondences, and natural season combine to make Kislev a time of preparation, hope, and spiritual awakening.