VERTICAL SUNDIAL FACE DESIGN #101 This dialface is designed for my location at longitude 111.95 degrees W. It is a South-declination vertical dial with a gnomon at the proper angle for this latitude and can be adjusted for a gnomon of any thickness. ( The Gnomon is the angled piece in the center of a sundial that casts the shadow.

Horizontal DialFace - with Equation of Time included to accurately correct for the varying length of the MeanTime 24 hour day. At some times of the year, apparent sun-time can be as much as 16 minutes away from clock-time. The Equation of Time tells you how many minutes fast or slow the sundial (apparent time) is running. The same correction applies to sundials everywhere. Designed for a pin-type gnomon, I use a length of welding rod embedded into wood at the proper latitude angle, which in Salt Lake City is 40.75 degrees.

Vertical DialFace with hourlines only corrected for longitude 111.95 degrees W. Mountain Standard Time, one of the 24 Time Zones each, in theory, spanning 15 degrees of longitudinal arc, with the entire world representing 360 degrees. In practice, some time-zone boundaries follow rivers or geographical lines that are more convenient. Sundial angle lines are computed as a deviation from the nearest meridian to the East (n-s line) that is a multiple of 15 degrees. For example, here in Salt Lake City the time zone change happens at the 105th meridian which is 6.95 degrees to the East. When the sun souths at 12 noon at the 105th meridian, it still takes another 27 minutes for the sun to south here in Salt Lake City. Hourlines are computed using times that are adjusted by 27 minutes.

This dial face is a vertical face with a small gnomon. Time is read at the end tip of the shadow which points to the hourly analemmic curves so no correction for the varying 24 hour day using the Equation of Time is required. The shadow will touch the two hyperbolic curves at winter solstice ( top curve ) and summer solstice ( bottom curve). The shadow will touch the straight horizontal line on the two equinox dates. The 24 hour day actually occurs only 4 times per year while Greenwich Mean Time, the system that our clocks use, is designed around a fictitious 24 hour day because that is infinitely more convenient.

A horizontal Dial Face including the Equation of Time and layed out in 30 minute intervals.

Military time vertical dial ( up to 1400 hours at which time 3:00 takes over) including the Equation of Time. Looks good at a large size. 60 minute intervals.

This dialface is designed to recline 60 degrees from vertical. Hourlines as time approaches noon become very compressed and the opposite happens after sunrise and just before sunset where the shadow moves very quickly across the dialface. The gnomon angle is 10.75 degrees starting from the convergence point of the hour angles.

A vertical dial with space for a wide gnomon, equation of time, latitude, longitude and declination on face. Elegant large number font.