- The base movement turns the date wheel every day at (or, typically, just before) midnight via the 31 teeth on that wheel.
- The single tooth on the date wheel drives the five-pointed cog. I gather that this must turn the month wheel two teeth—probably one tooth when changing from 30th to 31st and a second tooth when changing from 31st to 1st, though I do not see exactly how this works. (It looks like the date wheel finger would only turn the small cog one tooth per month, and the small teeth on that cog look like they would only interact with the longer teeth on the month cog.) On short months the long teeth on the month wheel are in turn are nudged by the second, shorter finger on the hour collar at about 3am on the 1st (while the date wheel is still showing 31), which causes the month wheel to advance the second tooth almost a day early, and this must cause the five-pointed cog to nudge the date wheel to advance from the 31st to the 1st (though again I am not sure exactly how that works).
- The long finger on the hour collar turns the day-of-week disk 1/14th turn at 6am and 6pm, resulting in that wheel making a complete turn every 7 days. Thanks to the long dash of colour on this wheel, one dot is shown 6am–6pm while two dots are shown 6pm–6am.
Watchfinder made a pretty good video about it, though slightly hampered by the owner of this particular watch having chosen just about the lowest-possible contrast colours for the indicator dots: https://youtu.be/28LYcZJ6hHE
- The base movement turns the date wheel every day at (or, typically, just before) midnight via the 31 teeth on that wheel.
- The single tooth on the date wheel drives the five-pointed cog. I gather that this must turn the month wheel two teeth—probably one tooth when changing from 30th to 31st and a second tooth when changing from 31st to 1st, though I do not see exactly how this works. (It looks like the date wheel finger would only turn the small cog one tooth per month, and the small teeth on that cog look like they would only interact with the longer teeth on the month cog.) On short months the long teeth on the month wheel are in turn are nudged by the second, shorter finger on the hour collar at about 3am on the 1st (while the date wheel is still showing 31), which causes the month wheel to advance the second tooth almost a day early, and this must cause the five-pointed cog to nudge the date wheel to advance from the 31st to the 1st (though again I am not sure exactly how that works).
- The long finger on the hour collar turns the day-of-week disk 1/14th turn at 6am and 6pm, resulting in that wheel making a complete turn every 7 days. Thanks to the long dash of colour on this wheel, one dot is shown 6am–6pm while two dots are shown 6pm–6am.
Watchfinder made a pretty good video about it, though slightly hampered by the owner of this particular watch having chosen just about the lowest-possible contrast colours for the indicator dots: https://youtu.be/28LYcZJ6hHE