The Octa five-day automatic Calendar

The annual calendar is the third complication to be integrated within the Octa automatic winding calibre, defined as the first automatic winding movement to ensure a minimum power-reserve of 120 hours (five days) enabling extremely précise time measurernent even when not worn.
The originality of each of the Octa complications is imposed by an identical mainplate for all models within the Octa collection. The mechanism must adapt to the milling and drilling required for other complications and must also be inserted within a thickness of just 1 millimetre.
Once main, François-Paul Journe has achieved the feat of integrating within this five-day automatic calibre a complication as significant as an annual retrograde calendar, while maintaining the dimensions of the mechanism at :30 mm in diameter and 5.7 mm thick.
The calendar which displays the day and month through two separate windows advances instantaneously and is self-adjusting for the months of 29. 30 and 31 davs.
The Octa annual calendar automatically inoves from month to month. It only needs to be advanced manvally ai the end of February, three years out of four. For non leap-years, the calendar must be moved from Februarv 28th to 29th by a single turn of the crown and the calendar automatically moves from February 29th to March 1st.