Tibet, 1950 AD., Trapchi mint in Lhasa, 5 Sho, KM Y 28a.

Tibet, Trapchi mint in Lhasa, 1950 AD.,
5 Sho (29 mm / 8,62 g), copper, type minted from 1947 to 1953,
Obv.: moon and sun over snow lion walking left, three mountains with clouds in background.
Rev.: the name of the Tibetan government starting on top (at 12 o´ clock): dga' ldan pho brang phyogs las rnam rgyal (spoken: Ganden phodrang tschogle namgye), each syllable written into one of the 8 pedals of a lotus flower. In the middle circle the date according to the Tibetan 60 year cycles (first line: rab byung / 16 lo 24 (1950 AD.) / plus value and denomination (sho lnga) in the last line.
KM Y 28a .

The date is calculated according to the Tibetan calendar, starting year 1026 and proceeding in cycles of 60 years. A coin dated 16th cycle year 22 therefore is: 1026 + (15 full cycles each 60 years) 900 years + 22 years of the 16th cycle: 1026 + 900 + 22 = 1948. The Rabjung are 60-year cycles, the first of which began in 1027 C.E. We are currently in the 17th Rabjung, which began on February 28, 1987.
The Tibetan Calendar dating system is based on a cycle of 60 Tibetan years, each of which usually has 354 days. History of Tibetan calendar, dates back to the 7th century, when Princess Wen Cheng brought Tang's calendar to Tibet, later Princess Jin Cheng embraced the same calendar. After the down fall of the Tibetan dynasty, Tibet became chaotic, and the disseminations of the Han calendars stopped, the Tibetans were thus left without a scientific calendar until 11th century. The first month of a year was fixed by the position of the third `zhong-qi' counted from the winter solstice as in the Han calendar. The Tibetan calendar is Solar-Lunar calendar.
Significance of Tibetan calendar stems from the fact that these calendars were particularly used for providing a working seasonal schedule for farmers, affiliating the enlightening date of Buddha and more importantly calculating the moon and sun eclipses. The proper way to add the leap month was arranged during the reign of Tang dynasty in the Han calendars, and thus the Tibetan calendars followed them. At the beginning, the Tibetan adopted the Indian way of naming the month according to the position of the full moon. Later, the Tibetan moved to the Han customs of naming each month numerically by beginning the month with the new moon.
5 Sho are the equivalent of 50 Kar or 1/2 Sang. In the year 1948 for 5 Sho one could have one's horse hooved. 5 Sho was also the daily salary of a Trapchi canal worker.