The Gondolo Calendario reference 5135G-010 is the only annual calendar Patek Philippe made in its Art Deco–inspired Gondolo line. Introduced in 2004 and discontinued in 2011 with no direct successor, it pairs the tonneau case with the annual calendar Patek Philippe introduced in 1996: it tells months of 30 and 31 days apart, so it only needs adjusting once a year, on March 1.
This is the -010 version, with the two-tone anthracite grey ("Ardoise") dial; the -001 has a silvered dial. Cased in 18K white gold, it measures about 38 mm across and 51 mm from lug to lug. The day, date and month sit in three arched windows, with a moon phase and 24-hour indicator at 6 o'clock, applied baton markers and Breguet numerals at 3 and 9. Through the sapphire caseback you can see the self-winding Caliber 324 S QA LU 24H and its 21K gold rotor.
Produced from 2004 to 2011. Offered without box or papers, with a Patek Philippe travel pouch, on its original Patek Philippe black alligator strap and 18K white gold tang buckle.