In 1969, Zenith achieved a horological milestone with the El Primero—the first automatic high-frequency chronograph operating at a 36,000 vibrations per hour and measuring time to one-tenth of a second. This innovation allowed for remarkable precision, setting a new standard for mechanical timekeeping. The El Primero remains an icon, continuously refined and reinterpreted. At Time+Tide, we celebrate its legacy with an exquisite watch selection featuring an open-work evolution of this historic movement.