"Umbrella dial" by
by H. Sonderegger
Last Update: 2022/09/17
Software SONNE runs on all Windows systems up to
Windows 11 (64-bit-systems too). The program and its
help files in chm-format are offered in German and
English. The language is selected in the help-menu. Right mouse-click displays popup-menues
for many cases. The Photo Gallery in the start window shows many of the
sundial types which are calculated by SONNE.
The calculations are done for any reference year between
1300 and 2500 and for all latitudes and longitudes. The transition to the Gregorian Calendar in Oct. 1582
All constructions are displayed on screen and can be printed on
any printer installed in Windows or saved as dxf-file (*.dxf for AutoCad, DeltaCAD,...) or HPGL-file
The program computes
* the time of sunset and sunrise, moonset and moonrise and
twilight (civil, nautical or astronomical)
* with time as input the position of the sun (azimuth and
* with azimuth as input the time of this sunposition
* the Equation of Time (EoT).
* tables of the declination of the sun or of EoT for any
reference year (between 1300 - 2500).
It is possible to printout all results and to save the tables as text files.
The program constructs for the given geographical position
(longitude and latitude)
* horizontal sundials
* vertical, inclining and reclining sundials (for any
* cylinder sundials (shepherd's dials, azimuthal cylinder dials, cylinder dials
with polar style )
* quadrant sundials (different types, also Gunter's Quadrant)
and 2 altitude sundials by Habermel with a new "Decliner version"-
* azimuthal sundials (azimuthal spider dial, stereographic dial,
* "umbrella dials" (specific type of
* horizontal altitude sundials ("Basho Hidokei")
* (simple) ring sundials (farmers rings), now for low latitudes and tropics(!) too
* compressed sundials by F. Sawyer (...
* "Sawyer Decliner, Type 1 and 2", a new idea for
portable vertical sundials indicating local mean time.
* mean time sundial by H. Hollander (...
* graph of equation of time for years from 1300 to 2500
* sun path diagrams for years from 1300 to
2500. Display in Caretesian (x/y) coordinates or in polar coordinates.
Additiionally horizon profiles can be calculated and included. (Time indication with longitude correction debugged.)
* Furtheron time of sunshine is calculated and displaed for any inclining and/or declining plane
within the Cartesian sun path diagram.
* overlay of coast lines is calculated for any horizontal, vertical, inclined or compressed sundials
(in 'Expert Mode' only)
Type of lines computed:
* hour lines for local time (mean and apparent)
* time of zone meridian
* temporal hours
In all types the time of start and end and the time interval can be
In horizontal / vertical / inclining sundials, in "umbrella
dials" and some types of cylinder dials it is possible to show additionally
* Babylonian hours
* Italian hours
* Lines for the sun's altitude
* a table with the angles of the hour-lines for true solar time
Also the start time, end time and
interval of these lines can be fixed.
Additionally, printout of coordinates for horizontal / vertical / inclining sundials and for umbrella
sundials is possible. Instead of printing the coordinates all data can be saved as ASCII-text-file.