Draws horizontal sundials featuring a graphical converter and movable ring (example). Uses millimetres for all lengths. Uses decimal degrees for all angles.

Type of dial required

Civil Time Dial with Daylight Saving Time using North American rules (second Sunday in March; first Sunday in November).

Civil Time Dial with Daylight Saving Time using European rules (last Sunday in March; last Sunday in October).

Civil Time Dial without Daylight Saving Time adjustment.

Hours To Sunset (reverse-numbered Italian dial).

Dial latitude
Longitude offset from timezone meridan -7.5° to 7.5° only, positive for a location east of the meridian. This setting is ignored for Hours To Sunset dials.
Dial diameter
Gnomon width
Ring widths
Material width Give dimension for Landscape orientation.
Material height Give dimension for Landscape orientation.
Calendars' short tick length Day marks.
Calendars' long tick length Five day marks.
Hour scale's short tick length Five minute marks.
Hour scale's medium tick length Quarter hour marks.
Hour scale's long tick length Hour marks.
Colour for the edges of the movable ring
Colour for minor divisions on the converter scale
Colour for hour lines
Colour for labelling aids
Line widths
Use double width lines for hour lines and hour marks
Gnomon offset Using anything but 0 is not recommended in most cases - see notes below.

Version 20200719. You are welcome to contact for general inquiries, suggestions for additional settings, and to report problems.

You may copy and adapt this web page and the associated Javascript for your own use, but you must retain this statement and the associated Javascript comments that acknowledge original authorship. Steve Lelievre asserts his moral right to be known as the original author of this work. © Steve Lelievre, 2018.

Note, this program is incomplete. To Do: southern hemisphere code is not yet fully tested (beta status).

For an excellent source of general information on sundials, visit the North American Sundial Society website.

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