34
GMT, Worldtimer, GMT Chronograph
Operating instructions2
Chronograph functions 
(calibre 3603 – fig. XXIII, calibres 9605, 9615 – fig. XXVII)
•  Pusher A : start – stop, start – stop, etc. 
  Timing to within 1/8 of a second for up to 12 hours.
•  Pusher  B : reset (after stopping).
Note: the chronograph function must always be stopped before the 
zero resetting function is used. Never push the chronograph’s two 
pushers (A and B) simultaneously (calibre 3603).