Labs / History
Calendar Gears
Twelve lunar months come up about eleven days short of a solar year, so a moon calendar slowly slides through the seasons. Turn the crank to run time forward, then add leap months and watch the calendar new year creep back toward spring — until the 19-year Metonic cycle locks the moon and sun back into step.
Year 1Month 1/12Season offset +0.0 dCycle 0.0 d/19yr
What to try
- With the pure-lunar scheme, where does the new year end up after ten years — still in spring, or a whole season away?
- How many leap months per 19 years does it take before the gold new-year dots stop wandering and cluster in one spot?
- At the Metonic setting, what does the “Cycle” readout say — how many days does the calendar slip across an entire 19-year cycle?
- Turn on the leap day. Does it help a lunar calendar, or does stacking it on top of the Metonic scheme push the alignment back off?
- Why does a 13-month year appear only sometimes, and what happens to the “season offset” the moment one is inserted?