The Octa five-day automatic chronograph with large date

Built-in reliability
Whether fitted with a chronograph, an annual calendar or with a powerreserve indicator, the Octa automatic five-day movement always measures 30mm x 5.7mm. In François-Paul Journe's most evolved construction, a single complex chassis integrates a variety of complications without changing its form or size. The ultra-thin chronograph work, for example, is built into the movement. This compact construction, without bolt-on modules, results in a robust and stable movement.
It is also the first automatic movement with a power reserve that maintains precision timekeeping for five days (120 hours) off the wrist. The Octa chronograph features zero restart (retour-en-vol) as well as zero stop functions and a 60-minutes register.
The watch displays Journe's patented date in separate large numerals and the hours, minutes and small seconds on Journe's trademark regulator dial.
The 1mm chronograph Journe has designed an ultra-thin version of the classic column-wheel chronograph, to fit into a 1mm-high space under the dial. This space is shared by the twin concentric discs of the large date display. The column-wheel has been flattened into a cam-wheel. Its profiled rim, instead of columns, acts on the chronograph levers.
A single sliding lever zeroes both the chronograph seconds and minutes, disengaging their brakes as it strikes specially profiled heart-pieces to zero the hands. These two innovations allow the entire chronograph work to be reduced to three mechanical levels.