Calendar CompliCations at a glanCe
Calendar complications in general are features on a watch dial that tell the date, month, year and might even account for leap years—which have an additional day, February 29, every four years. The first two are, quite frankly, quite common these days, since most watch brands have developed their own style of displaying dates and months. Calculating leap years, however, require an intricate mechanism, one that is able to count the passing of the years, and add one more day after three years in a row.
A calendar complication that includes all those four calendar features is called a perpetual calendar or, alternately, at least in Switzerland, a quantième perpétuel. The first watchmaker to offer that highly complex mechanism inside a wristwatch was none other than Patek Philippe, the last family-owned independent Genevan watch manufacturer. It was, to be precise, back in 1925 when the legendary house debuted the No. 97975 perpetual calendar timepiece. It not only accurately showed the date of different months (accurately moving between 30 and 31 days) but also automatically recognized leap years. Only one-time adjustment once every century was needed, because leap years, according to the Gregorian calendar, are