The annual calendar was Patek Philippe's own invention: a calendar that distinguishes 30- from 31-day months and needs correcting only once a year, at the end of February — the practical middle ground between a simple date and a perpetual. This reference marks the complication's thirtieth year, in rose gold with a sunburst sandy beige dial and a moon phase. What matters on examination: that the calendar advances correctly across a 30-day month end; that the moon phase is set exactly rather than approximately; and that the movement has been serviced within interval, since annual calendars are frequently left unrun for long periods. Confirmed through the desk. Maker: Patek Philippe. Reference: 5396R-016. Available through ELITA's private desk — verification review, discreet handling and storage. Price on request.