Clayton Boyer Clock Designs


Perpetual Calendar

I've been wanting to build a simple mechanical calendar for a long time, and this Perpetual Calendar is just that...simple, and yet it does so much. This calendar knows the correct end of each month and advances itself. Besides the day of the week, day of the month, month and sun sign, it also shows the moon's phases to an accuracy of one moon phase day every three and a third years. The calendar is perpetual and knows Leap Years and will only need to be reset one day in the year 2100 (and again in 2200 and 2300...I can hardly wait!). As you know, below the equator the moon is seen to be turning the opposite direction. This calendar has been designed to compensate for whichever side of the Equator you live.

The instructions take you on a simple step-by-step build from mounting the frame onto your wall, to completed calendar.

And now the improved Perpetual Calendar plans include a new Self-Resetting option:

Not being able to leave well enough alone, we have added to the original plans a new self-resetting mechanism. With this addition all that is required is to manually push the main lever to the left and release--the self-resetting clockworks mechanism does all the rest. It is so neat now to be able to stand back and watch this newly mechanized calendar going through all of its gyrations--especially at months end! I have redesigned the plans so that the self-resetting mechanism is an optional, easy add-on to the basic lever driven Perpetual Calendar.

You can see this Self-Resetting Perpetual Calendar in action on the video player below, or click here: Perpetual Calendar V.2 with Self-Resetting Option


If you have previously purchased the Perpetual Calendar plan and would like the additional plans for this self-resetting mechanism, you can request the update electronically by sending me your CCNow order number and your request to If you would like this update as printed pages, send a self addressed stamped envelope, your CCNow order number and your request to Clayton Boyer P.O. Box 451 Kenwood, CA 95452 USA

Below is a video of the first version of my Perpetual Calendar, made before I added the optional self-resetting mechanism:


As I receive them, I'll post other builders' interpretations of my Perpetual Calendar design here: Perpetual Calendar Flickr Pool

and on YouTube here: Perpetual Calendar on YouTube

Perpetual Calendar plans are available in TWO different formats. Please choose only one option:

The price of the paper plan delivered by mail is $50.00 plus shipping. If you would like to purchase Perpetual Calendar paper plans by mail (our usual method), click here:


If you would like to purchase electronic plans in dxf format and receive them via email, you must:

1. Have a CAD program that can read dxf's.

2. Have a valid email address that can receive a 5 MB attachment. Add to your safe senders list so we don't end up in your spam filter.

If you prefer the dxf/email option, you will not receive a paper copy by regular mail. Plans purchased with the dxf option will be delivered to your inbox as an email attachment after payment is received, usually within 24 hours. The price of the dxf plan delivered via email is $47.00. To purchase dxf plans via email for Perpetual Calendar by credit card, click below:

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