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Setting Your Moon Dial On Grandfather Clocks


Grandfather Clocks with Moon Phase

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. (See figure 5).


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 on 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 numbers 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 dial which is the full moon.

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 has started again.

Full moon dates 2020

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One of the most frequently asked questions by new clock owners is, “What is the purpose of the moon dial and what do the pictures or symbols stand for”? The question itself tells us just how much the world has changed. Today it is difficult for us to realize just how important the ever-changing phases of the moon were in times gone by. In the late 17th century, the moon dial was added to most long case clocks so that people could plan ahead for when the moon was full and travel at night was not so hazardous. Clockmasters endeavored to simulate and approximate the appearance of the moon, in each of its phases, on the face of clocks.

The arched dial was first used in clocks at the beginning of the 18th century and presented a real challenge to the makers of fine clocks. By approximately 1720, moving figures began to appear in this space, figures which moved back and forth with the swing of the pendulum. Among them were prancing deer, rocking ships, and Father Time with his scythe. At the time, there was no practical value to this feature on the clock, it was done simply to the delight of those viewing the clock. After motion had been added in the arch above the dial, the next step was to reproduce the progress of the moon from phase to phase.

The proverbial “Man in the Moon” was used on most dials with a landscape and/or seascape on the other half of the circle. A rocking ship was a frequent symbol of the sea, with a deer often representing the land. In our very modern world today, the moving moon section of the dial is more decorative than useful, but it is still a very sought after feature. Many beliefs concerning the moon and its effects have been recorded.

Among them:
• Sweep the house in the dark of the moon and you will have neither moths nor spiders.
• Trees planted at full moon will bear fruit.
• Plant peas and potatoes in the increase of the moon.
• The number of snows during winter is indicated by the number of days from the first snow in fall to the following full moon.
• Shingle the roof in the decrease of the moon (between the full moon and the next new moon) so the shingles are put on when the
horns of the moon are turned down and will not warp and rise up. The same holds true for boardwalks.

43 responses on Setting Your Moon Dial On Grandfather Clocks

  1. The owner of this company is a soft spoken, mild mannered gentleman who is a pleasure to do business with. Has a wonderful way of explaining things to you. I’m sure I taxed his patience trying to understand how to set the moon dial, yet never raising his voice in frustration, took all the time necessary to get through to me. Waited a life time for this clock, which is beautiful, many compliments on it as well. The owner is just an added bonus. Thanks ever so much, loved everything about it! Sincerely, Al Peterson

  2. i have a ridgeway grandfather clock with moon dial and ship, deer and 2 moons not sure which moon goes up for full moon also i have owned this clock aprox 15 years and never knew to oil it it stopped so we took off hood and cleaned (was not a speck dirty before opening hood) then started clock ran 15 hours stopped again. ordered oil from ronell in Grants Pass Or and oiled every point started up and have my fingers crossed. can you advise whch moon goes up to 15 for full moon thank you for your time lisa camille

    1. Hi Lisa,
      There are two moons on the dial itself and each moon is 29 1/2 days apart, so it makes no difference which one you use. If the clock continues to run, you will see each moon on totality 6 times a year. They will continue to alternate as long as the grandfather clock is running.


    2. Either moon will represent a full moon. The dial needs two so that when one moon phase is complete, the next one begins. It will take 59 days, two moon cycles, for the moon dial to make one complete rotation. So, which ever moon is closest, move to the top position when it is a full moon outside, to make it simple. Or you can calculate the days as explained above for a greater challenge between full moons!

  3. The most direct question seems impossible to get answered anywhere! I just want a “visual” as to what my “moon” display is supposed to look like TODAY, JULY 10TH 2015? Sound as like an answerable ? to me.

    1. Hi Vince,

      It is easy, but I don’t have an image.

      SOLUTION FOR JULY 10TH: turn the dial until the top of either moon is under
      the number 25 at the top of your dial.


      The full moon was on the 1rst of July.
      We are now 10days after the full moon.
      On your dial, the full moon is under the number 15..always.
      We are now 10 days after the full moon (15 + 10)
      The moon should be under the 25 on 07-10-2015.


  4. We have a Colonial gandfather clock and was directed to your website by a friend. The moon phase was not working so I reset it. I was told, growing up, to plant during a full moon. As the moon affects the ocean tide, it also pulls water closer to the surface of the soil. Interesting reading, this site is! Thank you!

  5. This is an awesome site. I actually won a grandfather clock with a moon dial. My dad received a grandfather clock one Christmas and I grew up with one so I love hearing the chimes. However, his clock did not have a moon dial. I was interested in the history as well as the operation of the moon dial. This site was so informative and helpful. Thanks so much!!

  6. I am so grateful to have finally gotten an answer that has eluded me since my grandfather built my clock in 1977. Thank you for the information!

  7. Just reset my grandfather clock after being away a week. This article made setting my moon very easy to understand. Thank you! No one else ever explained it so simply. Nice to start the day feeling smart!!!

    1. Hi Al…most newer clocks now have a moondial that doesn’t clock when you turn it. The older moondials would clock from day to day and could only be turned clockwise. The newer moondials may also turn in either direction. The newer ones are better in design. Thanks..Robert

      1. Thank you so much for the explanation of the moon dial.
        My grandfather built 2 clocks and I inherited one of them.
        I never knew what the pictures were and why they were there.
        Now I know and I just set the moon dial ☺️☺️

    1. Hi Ben, There is a pin attached to a gear on your dial that extends toward the front of the clock that passes and pushes the moondial once a day. This can happen if your pin is worn or the moondial itself is not perfectly vertical in all positions. If you are able to remove the dial, you will probably see the issue immediately.
      Good Luck,

  8. Hey out there!


    1. Hi Christina,
      There were a few grandfather clocks that were made with a faux moondial, but probably not the Sligh grandfather clock. It moves very slowly and some don’t notice the movement and think it is broken. Today it is two days after the full moon. Turn the moondial clockwise from the inside of the clock until the top of one of the moons is under the number 17 on the dial. The 17 is two days after the full moon. If it doesn’t want to turn…wait a few hours and it will later. I bet it will turn and work correctly.
      Good Luck…Robert

  9. Clockde, thank you SO much for clarifying how to set the moon dial!! I wound my clock last Friday like I always do, and it ran for about 25 minutes and then for some odd reason, stopped. However I left right after I wound the clock, and wasn’t aware it had stopped until I returned home last night. So I had to start from scratch, and your instructions made it so easy! Thank you!

  10. This may sound ridiculous, but I’ve had my clock for almost 40 years and I have never set the moondial because I didn’t know how. But today I did! Thanks for the info!!

  11. Please help me ? I’m not sure how to set the moon dialog my Emperor grandfather clock because the last full moon was on October 13th 2019 hope you can tell me where to start ?

    1. Hi Barbara..
      The full moon will occur again on 11-12-2019. The 15th day on your clock dial is the full moon, so if you set it on Nov 1rst, it will be 12 days until the full moon. Move the moon dial until the top of the moon is near the #12 of your dial.
      12 days before full moon on grandfather clock

  12. Thank you for sharing, we have an old grandfather clock that no one knew how to set the moon dial. Finally set it up correctly in 40 years!

    1. Hi Victor,
      I am glad you were able to set the moon dial on your grandfather clock for the first time. It is interesting to watch.

  13. Hello today is 11/ w5 2019 can someone tell me where moon should be on grandfather clock please? Tia

    1. Hi Mary,
      The next full moon will occur on December 12th. You want to turn the moon dial so the image of the moon is under the “15” on the moon dial at that date on your grandfather clock. If you wish to set it today (Dec 7th, 2019) The top of the moon should be under the number “10” on your moon dial which is 5 days before the full moon. It will stay correct as long as your grandfather clock continues to run.

  14. I can’t figure where to put my dial now on June 7th 2020. The last full moon was June 5th , 2020 and the next is in July . Can someone please help me ? My weights , the one in the center keeps falling down faster the the others for the past few days , i thought the moon dial might be the reason.

    1. Hi Barbara,
      The full moon was on 06-05-20. If the moon dial has been set, the moon on the dial would have been under the #15 on the dial. It is now the 8th (three days after the full moon), so the moon should be located under the #18 on your dial. The middle weight drops more quickly than the others when your chimes are turned off or not chiming at night.
      Thank You,

  15. just acquired a grandfather clock today date is 9/29/2020 where would I place to moon dial?
    And I have label inside the door that it should be oiled every 3 years. Where do I oil it and what type of oil. Your web site was very help full thank you

    1. Hi Joyce, The full moon will be tomorrow (October 1, 2020). Today is 09-30-20 which is one day away. This means the top of the moon should be under the number “14” on your dial.
      You have to take the clock apart to oil one so this is best left to a clock technician. The hands, dial, facia, and panels all need to be removed first.
      Good Luck,

  16. Thank you so much, because your information on how to set the moon phase was so informative and helped us set our Howard Miller grandfather clock made in Zeeland, Michigan. We love our grandfather clock that we had since early 1980s . Recently, we Were told they are not in style anymore and I should get rid of it! However, I replied to that decorator….I do not care, we love having it and it is our style not the worlds style say so!

  17. This is just a Thank You note!

    We have a Hermle Westminster-style clock, a small one, for a few years now, and this site was the site with the easiest explanation of how to set the moon dial when I needed it years ago. And I don’t need it that much now (I know how to do it by heart), but sometimes it’s still the best resource 😉

    Cheers from The Netherlands!

  18. Thanks for making this website and answering all the questions I have had about my clock.
    I really appreciate your time and effort.

  19. Hello, can a clock be retrofitted with a moon-dial function or would the complete movement need replaced? I have a Howard Miller Chateau grandfather clock with the Tempus Fugit face and would like to have the moon phase dial. Thank you.

  20. Sir
    Recently I bought a quartz lunar motor which goes round for 29.5 days —one round But preparing a dial ???? As it may need adjustments on and off. If so it defeats the continuous running
    In almanacs they add up two lunar days as one day. Confusing. Suggest a dial and I am ready to buy
    Best wishes
    God bless

  21. Are the 2 moons on the dial the same? Or are they 1/2 day out of phase? The reason I ask is that I want to know if there is a convention as to which clock moon is more appropriate for full moons that occur between midnight and noon and which clock moon is more appropriate for full moons that occur between noon and midnight. I am assuming that the clock is set up so that the moon phase change occurs between 1am and 3am. Would one moon not be at 15 during a full moon yet if you rotate the moon dial, the other one would be at 14.5 or 15.5 (not 15)?
    Would a 7pm full moon better be a 15 or a 14.5? Would a 5am full moon better be a 15 or 15.5?

  22. Clockde has not responded since 2020. I loved following the Q&A. I hope all is well? Does anyone know Clockde personally so we can inquire?
    Thanks Victoria
    Powhatan Virginia USA

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