Patek Philippe · Automatic

26-330 S QR

The 26-300 automatic base with a retrograde perpetual calendar module above it, made for reference 6159. The date runs along an arc between eight and four o'clock and snaps back to the first at midnight on the 30th or 31st, which is the mechanically demanding part of the arrangement. The base itself descends from the 315 and 324 workhorses.