This year marks two decades since Harry Winston launched its Ocean Collection. The new Ocean Biretrograde Perpetual Calendar Automatic gives the graphic codes of perpetual calendar watches a total overhaul. Architectural and geometric, this 42mm timepiece in rose gold or white gold displays a biretrograde perpetual calendar, bringing together the indications relating to the almanac – day, date, month, leap years and moon phases. Its mechanical movement also allows the watch to display the correct number of days in each month.

From £43,100; harrywinston.com