Georgia Clock Repair

200 Meadow Dr Cumming, Georgia   30040   (770) 781-9536

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 "Windinng the  Clock" Poem

 "Grandfather's  Clock" Song

 Case Restoration  Examples


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Antique Moon Dial

Setting the Moon Dial

The moon dial is designed to show the shape of the moon as it appears in the sky, the number alongside
it being the lunar date. The numbers on the dial are of the Lunar Calendar and NOT the calendar date.
A lunar month has consistently twenty nine and a half days in every month and these are usually lettered
in Arabic (English) numerals. The Full Moon always occurs on the 15th day of the Lunar Calendar. If it
were a full moon today, the image of the moon on the dial would be centered below the 15 on the dial.
There are two moons on the dial and it makes no difference which one is under the 15. Grandfather
clock moon dials consist of a round disk displaying two pictures of the moon. A one half rotation of
the disk occurs every 29.5 days which is one lunar cycle.
If you have a Grandfather Clock with moon phase, follow these instructions. To set moon dial, apply
slight pressure with your fingers to the front of the moon dial. Rotate the moon dial Clockwise until
the moon is directly below the number 15 on the dial.

Traditional Moon Dial on a Grandfather Clock

If the moon dial will not rotate, wait 6 hours and try again. Never force the moon dial as it should
move easily. It may be in the 3 hour cycle where it is moving the dial…wait a few hours and you should
be able to easily move the moon phase dial.
1) Using an almanac, lunar calendar or the chart below to determine the date of the last full moon.
2) Position the moon dial so the moon is under the 15 on the dial.
3) Count the number of days past the last full moon on a calendar.
4) Turn the moon dial Clockwise one click for each of the number of days past the last full moon.
The moon dial is now set and will indicate the proper moon phases as long as the Grandfather Clock
operates continuously.


Let’s pretend today is the 20th of any month.
Your almanac or lunar calendar says the full moon occurs on the 25 of this month.
(this means the full moon is 5 days away..right?)
Set your moon dial on your Grandfather Clock so the moon is under the 10 on the dial which
is 5 days before the 15th day the the dial which is the full moon. Done!
If the Grandfather Clock with moon phase dial stops for more than 24 hours, the moon dial will
also stop, and must be reset when the Grandfather Clock is started again