This watch is part of a limited series of 100 pieces, produced in 1994. The " Hebraika " watch was created by Alain Silberstein " watch architect" in Besancon, the capital of the French watchmaking industry. It ' s a watch with a Hebraic perpetual calendar: it automatically passes from the 29th clay of the month to the 1st clay of the next month. It takes into account automatically the 13th month of embolismic year. (Adar 1). The 2nd and 3rd months of the year can have 29 or 30 days according to the year. As this number of clays does not correspond to a regular cycle, these 2 months have 30 clays. You must check the color of the year on the dial on the back of your watch to see if the month has 29 or 30 clays. If is is a 29 clays month, your must manually correct it on the 29th clay to skip the 30th and go to the 1st of the following month. Judaism makes the beginning and the end of a clay coinside with sunset at 6 p.m. corresponding by convention to 0.00 hours for the calculation of the 1-lebraic calendar. Thus, this is the time when the date changes. For a more reader friendly dial, the years are positioned on a small dial on the back of the watch. This watch was developped in association with the Geneva master watchmaker Svend Andersen. Hebraic months Corresponds nt civil mouths Tichri: 30 clays Sept/Oct 'Hechvan: 29 or 30 days Oct/Nov Kislev: 29 or 30 clays Nov/Dec TeveC 29 clays Dec/Jan Chevat: 30 clays Jan/Feb Adar I::30 clays (Extra month) Adar or Adar II: 29 days Fev/Mar Nissan: 30 clays Mar/Apr Iyar: 29 clays Apr/May Sivan: 30 clays May/Jun Tamouz: 29 clays Jun/Jul Av: 30 days lul/Aug Eloul: 29 clays Aug/Sep Summary of the Chronometer trials : Mean clayly rate in the different positions: 1,1 Mean variation: 0,6 Maximum variation: - 1,5 Greatest difference between the mean daily rate and any individual rate: 2,1 Vitiation of rate per 1° centigade: - 0,10 Secondary error: Rate resuming: 0,0 77re values. are indica(ed in seconds.