Considering the fact that ecclesiastical rules do not precisely say that a church must be directed “to the East” or “to sunrise”, it should always be checked if there is a connection between the orientation of a church and geometry of the Sun. In this paper, such examination is performed on the example of the church of St. John (the 13th century), one of four churches of the Studenica monastery, in the following way: 1) using gnomon method, the azimuth of the main longitudinal axis of the church is measured; 2) the altitude above the horizon of the point in which the extended axis of the church touches the true horizon is determined by cartometry; 3) the most probable dates when the Sun rises at that point are determined: May 7th according to Gregorian calendar, or April 30th according to Julian calendar, in the 13th century. The applied method is described in details and it can be applied for the analysis of the orientation of any other medieval church. This method can determine the time when the church was founded, as well as the fact if the church is original, or possibly erected on the foundations of some older sacral object.