The legendary El Primero chronograph movement reveals its heart beating at 36,000 vph through a now legendary opening on the dial of the constantly evolving Chronomaster Open line by Zenith which now features a large date and the brand’s exclusive double celestial indication. The paths of the sun and moon are displayed by means of two superimposed discs: the transparent upper disc bears two polished metallised moons, revealing the lower disc bearing the day and night indications. They rotate at the respective rates of 59 days and 24 hours. The Chronomaster Open Grande Date Moon & Sunphase sets a fine stage for its useful complications on a sunburst dial with circular satin-brushed chapter ring and counter, providing glimpses of a meticulously decorated movement and celestial discs turning beneath a guilloché dome. Loyal to the aesthetic codes of the line, the new model comes in a generously sized steel or pink gold case fitted with round vintage-style pushers.