What is a calendar? This can not be the name suggests - calendar is not a watch can display 10,000-year date. Perpetual Calendar English name is Perpetual Calendar, the English meaning is the eternal calendar. It recognizes the current month, knows the current year, and even knows if this year is a leap year. It will automatically be embedded in the 29th day of February in a leap year. So, as long as the watch works well, the only time you need to adjust the date is at the end of February every 100 years, which is not a leap year, such as 2100. Rather than the calendar itself, a top technology in the watch industry, it is better to say that it is a beautiful vision of watchmakers - until now, there has not been a real sense that there is no need for adjustment in a million years Watch that shows the date of the day. Moreover, judging from the existing technical conditions, it is an impossible task to really make a wristwatch that does not need to be calibrated forever. Who invented the calendar According to the literature, the French philosopher Diderot, in his encyclopedia compiled in 1765, referred to a calendars made by the Swiss watchmaker Ferdinand Berthoud called "Everlasting". Later, another 18th-century master watchmaker, Jean Antoine Lepine, once recorded that a master named Lepine had dedicated Louis Vuitton's large, complex pocket watch, a collection of three questions, time equations and calendar functions. According to speculation, invented the tourbillon Breguet is likely to visit Lepine for a period of time as a teacher. This may also be the reason that he invented the world's first calendar pocket watch. Perpetual calendar movement design is not complicated, including the unique star wheel structure, the lunar month structure and the Maltese cross-shaped leap year counter and so on. These structures were well known as early as the 19th century. But the first perpetual calendar watch is by Patek Philippe was made in 1925 and sold to Thomas Emery in 1927. It just used a pocket watch movement that was made as early as 1898. This number 97975 movement not only shows the date, day of the week, month, but also shows the function of moon phase profit and loss. All the pointers on this watch have instantaneous jump bodies, even today it is staggering. Ten years later, in 1941, when the world was still in full swing, Patek Philippe introduced the world's first mass-produced perpetual calendar watch PP1526. How to maintain calendar watch? Since the perpetual calendar mechanical institutions have their own permutations and combinations, the adjustment after stoppage is quite complicated. Traditional calendar adjustment, is to rely on a variety of tuning buttons to complete the operation, these buttons are located on the side of the case, the need for the use of specialized tools. Now there are some watches for the convenience and practicality for the purpose, using the easiest way to adjust, as long as the crown out, adjust the calendar in different stalls, weeks and other parameters can be. If you trouble, you can send it to the watch shop to be adjusted. However, people who really love the table, it will not stop the perpetual calendar table, long-term wear, it will put it in the box. Poly fashion watch mall Recommended reading: Quartz watch is good or mechanical watch good ladies watch brand list the world's top ten watch brand watch list Ji'An ZhongXiang Natural Plants Co.,Ltd. , https://www.zxnaturaloils.com