Thirasia is a small Greek island situated to the west of Santorini in the Cyclades. Its population is about 250 people and its inhabitants are mostly occupied with agriculture. The only track of the island will lead you to the church of Agia Irini (Saint Irene) which is said to have given Santorini its current name (Santa Irini - Santorini).
The Church of Panagia the Giatrissa (the Physician) is found in Potamo in Thirasia and is dedicated to the Nativity of the Theotokos (September 8).
The celebration of the feast of Panagia the Giatrissa takes place on September 21st because the church was built in the 1950's by a family who were Old Calendarists, and when the church changed from the Old to the New Calendar (there is a 13 day difference between both calendars) the then Bishop did not change the feast day because the celebration of the church on that date was deeply embedded among the inhabitants.