Heliograph is a circular calendar in an A1 format. It visualizes the changing day length and time change throughout the year. Thereby it serves not only as an decorative element, but also as an informative artifact.
Calendars exist in all kind of shapes: advent calendars, wall calendar, pocket calendar, digital or analog, beneficial or decorativ – the list goes on forever.
My calendar isn’t supposed to be practical, but to visualize the changing day length throughout the year.
Heliograph was created with a combination of Adobe Illustrator and Processing. An online-tool helped me to get and save the data of the calculated sunrise and sunset in Osnabrück for all 365 days of 2015. The plan was to create a line for every day and arrange them in a circle. The length of one line depends on the day length of the incidental date. My first attempts to draw these lines manually in Illustrator failed miserably (or more precisely: were foiled by my own listlessness to draw more than 365 elements).
Processing provided a solution with just a few lines of code. A loop sifts through a CSV file, takes the first value and draws a vertical line with the value set as the length. Then the whole canvas rotates by 0.986° (360° of a circle divided by 365 days of a year) and the loop reruns this process with the next value. A library exports vectors of the created image as a lossless PDF which can be processed further with Adobe Illustrator.
I chose a combination of Letter Gothic Mono and Std for labeling the lines. This monotype font allows a consistently design without bringing along the typical „monotype-look“. The font for the core and legend at bottom is Frutiger Next Light Condensed.
Feast days and weekends are marked by a different color and a thicker stroke. The yellow background is divided into two shapes at the beginning and end of summertime to mark annual the time change. The font turns at these points by 180° to stay readable.