====== 1930 ====== * [[Patek Philippe]] manufactures the first [[watch]]es with [[perpetual calendar]] in single copies. * The companies [[Omega]] and [[Tissot]] unite at the initiative of [[Tissot, Paul|Paul Tissot]], who is also managing director of Omega, to the [[SSIH]] group, which later becomes the nucleus of the [[SMH]] and then of the [[Swatch Group]]. * [[Lip]] produces the first [[tourbillon]] wristwatch. <- [[1929]] | [[1931]] -> {{tag>Year}}