Analemmatic sundials and compass for Habana

Coordinates used in calculations: 23°07′ и 82°22′. All analemmatic sundials indicate real sun time. It means that average lap time will vary from the indications within ±15 minutes according to equation of time.

Civil calendar

Analemmatic sundials for Habana

This variant presents usual calendar and hour marks with longitude correction. It may be used in Habana as follows:

  1. To know the time.
    If you know cardinal directions, just orient the card on flat horizontal surface accordingly, and put a vertical stick. When properly placed on the gray schale, it will drop the shadow in the derection of civil time. As far, as there is no DST on Cuba it will work all year long.
  2. To know the North.
    If you know current time (UTC-5h), just put a vertical stick on the gray scale, according to the day of the year. After that twist the card on the surface in order pin's shadow to fall in the direction of current time. Blue arrow "Norte" will point to the North.
Sun icons mark main annual events:
Spring equinox - 18-19 of March;
Summer solstice - 22 of June;
Autumnal equinox - 23 of September;
Winter solstice - 22 of December;

Here is a refference to the file in scalable emf-format.

Zodiac calendar

Analemmatic sundials with Zodiac calendar

This variant presents Zodiacal division of year based on Sun's longitude as follows:

Aries (Sun's longitude 0°);
Summer solstice (Sun's longitude 90°);
Autumnal equinox (Sun's longitude 180°);
Winter solstice (Sun's longitude 270°);

This sundials show true local time, thus, hour marks are symmetrical and true noon mark lays on meridian gray scale. You can download a scalable EMF-format of the sundialshere. At the meridian 75° to the West (GMT - 5h) such sundials may be used for determining zone time.

Here are a few photos with different objects used as a vertical gromon.

6 of January, 2017