The writer of this blog post has always been a sucker for a clock with a moonphase dial, sometimes also referred to as moondials, whether moonphase grandfather clocks, moonphase mantel clock or bracket clock, or moonphase wall clock. And watches too!
With antique clocks, dials with a moonphase were especially prized, and were found most often, when they were found, on grandfather clocks or floor clocks. The lunar cycle is 29 1/2 days, which is one full revolution of the moondial on the moonphase clock. When there is a full moon outside, the clock is supposed to show a full moon at the top center of the moonphase dial. It will take another 29 1/2 days to be in the exact same position again. In the olden days, these days were actually used by farmers to help to know when to plant crops. They were also of use for people traversing the oceans, although a movement that would work on a clock with enough reliability was invented later and also had multiple uses for navigation and charting voyages.
In more recent years, moondials are seen on many types of clocks. They are also on wristwatches too, as well as some antique pocket watches. Many clocks, particular in the relatively lower price ranges, and generally with all chain-driven mechanical grandfather clocks, the moonphase dials are faux dials (the nice, and French, word for fake), and are stationary and do not move. hey are for decorative purposes only. Most higher-end cable driven grandfather clocks, particular by makers such as Howard Miller Clocks, Hermle Clocks, and Ridgeway Clocks, have working moonphase moondials on their grandfather clocks.
A working moonphase dial on a new or antique grandfather clock is a great feature, if one can afford a clock in that generally somewhat higher grandfather clocks price range. Keep an eye out for grandfather clock discounts and individual grandfather clocks for sale that have this feature. You very likely will not be disappointed, whether a grandfather clocks enthusiast or not.
Howard Miller Stewart Grandfather Clock Model 610-948 with working moonphase dial