The simplest and most commonly used of all calendars is probably the single calendar. People wearing single calendar watches can be seen almost everywhere in the daily living environment. In terms of appearance, the window-type calendar is usually designed at three o'clock or six o'clock on the dial, such as this Shanghai brand automatic mechanical waterproof steel belt casual business couple watch SH3019. However, because modern people are more pursuing visual novelty and freshness, many watches adopt different designs for the opening position of the calendar. However, no matter how the position is changed, due to structural limitations, basically the position of the date is close to the edge of the dial.
The annual calendar is the first step towards automated calendar calculation. The display includes day, date, and month display, and the window or pointer design makes reading easier. Pointer type calendars all use scale records as objects, while pointers are used as indicating tools. Window-type calendars display calendar records directly by a calendar disc, and calendar actions are completed by the rotation of the disc. Another notable feature of the annual calendar watch is that its mechanism can distinguish between the 30th month and the 31st month. The only error comes from the transition from the end of February to the beginning of March, so it only needs to be manually adjusted once a year. The best Breitling Avenger replica watches at captainthewatch.co.
The annual calendar cannot identify the leap month of a leap year, so watchmakers developed a more complicated perpetual calendar. Among the mechanical watches, the annual calendar table and the perpetual calendar table are all complicated types of watches. The perpetual calendar is more difficult to design due to the problem of dealing with leap year dates, so many watches also have a leap year display. Taking into account the change of the month (including the month of the leap year), it can be displayed up to 2100 (the next century that is not divisible by 400). Nowadays, there are very few watches with real perpetual calendars, that is, they do not need to be adjusted every 100 years and 400 years, which is called a mechanical wonder.