What is an annual calendar and how does it differ from a perpetual calendar?

An annual calendar automatically adjusts for months with 30 and 31 days. It only needs manual correction once per year — on March 1, because it cannot account for February's 28 or 29 days. A perpetual calendar also tracks the leap year cycle, so it handles February automatically and needs no correction until the year 2100 (when the Gregorian calendar skips a leap year). Annual calendars are thinner and simpler mechanically. Perpetual calendars are more complex and typically found in the Grand Complications collection.

How does the World Time complication work?

The World Time (Caliber 240 HU) displays all 24 timezones simultaneously on the dial. An outer city disc lists a representative city for each timezone. A 24-hour ring rotates continuously, showing day/night status for each zone. One press of the crown advances the local hour by one, automatically adjusting all other timezone displays. The center of the 5230 dial features a hand-guilloché world map. Reading any timezone takes a glance at the city disc aligned with the corresponding 24-hour position.

What is the difference between the Patek Philippe Complications and Grand Complications?

Complications include functions like annual calendar, standard chronograph, world time and moon phase — technically sophisticated but with fewer interacting components. Grand Complications require at least two major complications in one movement: perpetual calendar, tourbillon, minute repeater or split-seconds chronograph. The 5270 perpetual calendar chronograph sits at the boundary between the two collections. Complications are more wearable daily; Grand Complications are collector-grade horological statements.

What is the moon phase display on the 5205G?

The moon phase aperture on the 5205G shows a gold moon disc rotating beneath the dial at 6 o'clock. It tracks the 29.53-day lunar cycle, displaying the current moon phase — new moon, first quarter, full moon and last quarter. Patek's moon phase mechanism is accurate to within one day every 122 years. The disc features a blue sky background with applied gold moon and stars.

Are Patek Philippe Complications suitable for daily wear?

Yes. Annual calendar models (5205, 5396) and world time references (5230) are automatic movements with 45-hour power reserve — designed for regular wear. The annual calendar tracks the date automatically with minimal intervention. Water resistance is 30 meters (standard for dress complications). The primary care consideration is the leather strap, which should avoid prolonged moisture. For daily sport wear with higher water resistance, the Nautilus with its integrated bracelet is the better choice.