A replica Villeret perpetual calendar is a copy of the Blancpain Villeret Quantième Perpétuel. The original costs about $50,000. Replicas sell for $200 to $800. They use automatic movements from China or Japan. The dial shows day, date, month, leap year, and moon phase. Most replicas get the layout right. Few get the leap year indicator correct.
Movement
Original Blancpain uses caliber 5954 with 72 hours of power reserve. Replicas use a modified 2824 or a Chinese clone. Power reserve is 38 to 42 hours. The perpetual calendar module is a bolt-on plate. This plate adds 2.5 mm to the thickness. Replicas run at 28,800 vibrations per hour. Accuracy is plus or minus 20 seconds per day.
Case and Dial
Original case is 40 mm wide and 11.5 mm thick. Steel or rose gold. Replicas use 316L stainless steel. Thickness is 12.5 to 13.5 mm. The dial has a white or silver opaline finish. Applied markers are gold on the original. Replicas use gold plating or polished steel. The moon phase disc has a printed moon. Original has a laser-cut moon.
Functions
The perpetual calendar shows day, date, month, leap year, and moon phase. The date hand is a blued steel pointer on the original. Replicas use a painted hand. The leap year indicator sits at 12 o'clock on some models. On replicas this indicator often does not move. The moon phase advances once per lunar month. Replicas may skip or stick.
Price Tiers
Low tier: $200 to $300. Movement is a basic 2813. No real perpetual calendar. Date and month are fake. Mid tier: $400 to $600. Modified 2824 with a calendar module. Functions work. High tier: $700 to $800. Closer case shape. Better finishing. Still not a true perpetual calendar.
How to Check
Look at the leap year indicator. Set the date to February 28. Advance the time past midnight. A real perpetual calendar jumps to March 1 in a non-leap year. A replica often jumps to February 29. Check the moon phase. A real moon phase has a 29.5-day cycle. A replica may have a 31-day cycle. Check the crown position. The original has three positions. Many replicas have two.