Tibetan calendar

There were different traditions of naming years () in Tibet. From the 12th century onwards, we observe the usage of two sixty-year cycles. The 60-year cycle is known as the Bṛhaspati cycle and was first introduced into Tibet by an Indian Buddhist by the name of Chandranath and Tsilu Pandit in 1025 CE. The first cycle is the rabjyung () cycle. The first year of the first rabjyung cycle started in 1027. This cycle was adopted from India. The second cycle was derived from China and was called Drukchu kor (, ). The first year of the first Drukchu kor cycle started in 1024. The cycles were counted by ordinal numbers, but the years within the cycles were never counted but referred to by special names. The structure of the drukchu kor was as follows: Each year is associated with an animal and an element, similar to the Chinese zodiac. Animals have the following order: : Elements have the following order: : Each element is associated with two consecutive years, first in its male aspect (pho), then in its female aspect (mo). For example, a male Earth-Dragon year is followed by a female Earth-Snake year, then by a male Iron-Horse year. The sex may be omitted, as it can be inferred from the animal. The element-animal designations recur in cycles of 60 years (a sexagenary cycle), starting with a (male) Wood-Rat year. These large cycles are numbered, the first cycle starting in 1024. Therefore, 2005 roughly corresponds to the (female) Wood-Rooster year of the 17th cycle. The first year of the sixty-year cycle of Indian origin (1027) is called rab-byung (same name as the designation of the cycle) and is equivalent to the (female) fire-Rabbit year. : Years with cardinal numbers Three relatively modern notations of cardinal numbers are used for Tibetan years. On Tibetan banknotes from the first half of the 20th century cardinal numbers can be seen, with year 1 in 255 CE, which is a reference to the legendary 28th Emperor of Tibet, Thothori Nyantsen. Since the second half of the 20th century another year notation has been used, where the year of, for example, CE coincides with the Tibetan year of . This relatively modern year notation is referred to as Bö Gyello (bod rgyal lo). In this era the first year is 127 BCE, dated to the legendary progenitor of the Yarlung dynasty, Nyatri Tsenpo. In Tibetan calendars of the second half of the 20th century and on Tibetan coins cardinal year numbers are found with the indication of raplo, where the first year coincides with the first year of the rabjyung-cycle, that is 1027. Rab lo 928, for example, is the year of 1954 on the western Gregorian calendar. : ==Months==

During the time of the Tibetan Empire (7th – 9th century) Tibetan months () were named according to the four seasons: :First spring month (dpyid zla ra ba), middle spring month (''dpyid zla 'bring po), last spring month (dpyid zla mtha' chung''), :first summer month (dbyar zla ra ba), middle summer month (''dbyar zla 'bring po), last summer month (dbyar zla mtha' chung''), :first autumn month (ston zla ra ba), middle autumn month (''ston-zla 'bring-po), last autumn month (ston zla mtha' chung''), :first winter month (dgun zla ra ba), middle winter month (''dgun-zla 'bring-po) and last winter month (dgun zla mtha' chung''). From the 12th century onwards each month has been named by the 12 animals of the Chinese zodiac: :stag, (Tiger), yos (Hare), brug (Dragon), sbrul (Snake), rta (Horse), lug (Sheep), sprel (Monkey), bya (Bird), khyi (Dog), phag (Boar), byi ba (Rat), and glang (Ox). With the introduction of the calendar of the Kalacakratantra in the second half of the 11th century, months were also named via lunar mansions within which, roughly speaking, a full moon took place each month: In the second half of the 13th century the famous ruler Drogön Chögyal Phagpa introduced the system of counting the month by ordinal numbers, the so-called Hor "Mongolian" month: All these systems of counting or naming months were used up to modern times. ==Days==

There are three different types of days (), the , the and the . The first two of these days are astronomical days. The time needed for the mean Sun to pass through one of the twelve traditional signs of the zodiac (the twelve ) is called (solar month). One-thirtieth of one solar month () is one , which might be called a zodiacal day, because there is no equivalent name in Western terminology. The time needed by the Moon to elongate 12 degrees from the Sun and every 12 degrees thereafter is one tithi (, "lunar day"). The lengths of such lunar days vary considerably due to variations in the movements of the Moon and Sun. Thirty lunar days form one lunar or synodic month (), the period from new moon to new moon. This is equal to the time needed for the Moon to elongate 360 degrees from the Sun (sun to sun). The natural day () is defined by Tibetans as the period from dawn to dawn. Strictly speaking, the months appearing in a Tibetan almanac, called by us Tibetan calendar months, are not the same as lunar or synodic months (), which can begin and end at any time of day. In Tibetan, there is no special term for a calendar month containing whole days. These calendar months are just called (month). A Tibetan calendar month normally starts with the week day or natural day ( or ) in which the first tithi () ends. A Tibetan calendar month normally ends with the week day or natural day ( or ) in which the 30th () ends. In consequence, a Tibetan calendar month () comprises 29 or 30 natural days. In the sequence of natural days or week days, there are no omitted days or days that occur twice. But since these days are also named by the term together with a cardinal number, it happens that certain numbers or dates (the corresponding tithi) do not occur at all () or appear twice (). The are counted from 1 to 30 and it can happen that a Monday with the lunar day number 1 () is followed by a Tuesday with the moon day number 3 (). On the other hand, a Monday with the lunar day number 1 () may be followed by a Tuesday with the lunar day number 1 (). In other words, it happens quite often that certain dates do not appear in the Tibetan almanac and certain dates occur twice. But there are no natural days or week days that occur twice or which are omitted. The days of the week () are named for astronomical objects. : Nyima "Sun", Dawa "Moon" and Lhakpa "Mercury" are common personal names for people born on Sunday, Monday or Wednesday respectively. ==History==

During the time of the Tibetan Empire, the twelve months were named according to the four seasons of the year, and the year started in spring. and later used a Chinese astrological system, Tib. byung rtsis, which focuses on twelve animals and the five elements to describe patterns of events. The Indian and Chinese systems were joined by the Buddha's teachings found within the Sutra Avatamsakra and the Tantra Kalachakra to develop the Tibetan astrological calendar. Beginning in the 12th century, the years were named after the 12 animals common in the Chinese zodiac. The translation of the Kalachakra Tantra in the late 11th century CE marked the beginning of a change of Tibet's calendar. This tantra references the Indian astronomical calendar system with its calculations that follow the progression of the constellations - the five planets, and the sun and moon eclipses. As the original teachings of the Kalacakra were taught by the Buddha himself, two hundred years later, the Kalacakra calendar was officially adopted as a Tibetan calendar by the Ü-Tsang king Drogön Chögyal Phagpa, in the second half of the 13th century. A distinct Tibetan calendar was developed in 1284 by the lineage of the Gyalwang Karmapas, the Tsurphu tradition calendar. This Tsurluk calendar is based on the 3rd Karmapa, Rangjung Dorje's astrological treatise called The Compendium of Astrology (Tib. rtsis kun bsdus pa), a treatise from which many later treatises authored by the subsequent Karmapas and by Jamgon Kongtrul the Great evolved. The Tsurluk calendar is still overseen by Tsipa Gelek Dhargay, at the 17th Karmapa, Ogyen Trinley Dorje's seat in Rumtek, Sikkim, India. In 1447, a Tibetan astrologer Phukpa Lhündrub Gyatso composed an astrological treatise called The Oral Teachings of Pundarika (Tib. pad dkar zhal lung). His work founded the Phukpa calendar which is the main calendar of Tibet. This main Tibetan calendar, the Phukpa, was modified many times during the subsequent centuries, and it remains a luni-solar calendar. == See also ==

• (Sanskrit) Kalacakratantra. (Tibetisch) mChog gi dang-po sangs-rgyas las phyung-ba rgyud kyi rgyal-po dus kyi 'khor-lo. • Grags-pa rgyal-mchan: Dus-tshod bzung-ba'i rtsis-yig • sde-srid Sangs-rgyas rgya-mtsho: Phug-lugs rtsis kyi legs-bshad mkhas-pa'i mgul-rgyan vaidur dkar-po'i do-shal dpyod-ldan snying-nor • karma Nges-legs bstan-'jin: gTsug-lag rtsis-rigs tshang-ma'i lag-len 'khrul-med mun-sel nyi-ma ñer-mkho'i 'dod-pa 'jo-ba'i bum-bzang == Secondary sources ==

• Svante Janson, Tibetan Calendar Mathematics • • • • • • • • • • • • ==External links==