The customs and rituals in Strandzha are related to specific days of the year, which in most cases coincide with the church holidays of the Christian calendar. They are traditionally divided into a summer (beginning on St George's Day, 6 May) and a winter period (beginning on St Demetrius' Day, 26 October). The largest festival in Strandzha is celebrated in mid-August in the historic area Petrova Niva in commemoration of the Ilinden-Preobrazhenie Uprising.