Does Sunrise Day Correlate with Eastern Orientation of Byzantine Churches on Significant Solar Dates and Saint's Days? A Preliminary Study

Abstract

Abstract A preliminary investigation into the orientation of twelve Greek Byzantine churches towards the east is made in relation to the day of sunrise. Measurements were carried out using magnetic compass with inclinometer and GPS (azimuth, latitude, angular altitude of horizon) while declination corrections included a) local magnetic declination and b) refraction. The position of sunrise in the horizon as well as during morning hours was computed with in-house software. Accounting for the differences between Gregorian and Julian calendars, orientation of the nave towards spring and/or autumn, i. e. around the two equinoxes, was found for most churches. Orientations toward the summer solstice and the name day of the saint were also found.