Roodmas (from Old English 'rood' rod, cross, and 'mas', mass), held on May 3, was the celebration of the Feast of the Cross observed in some Christian churches and rites, particularly the historical Gallican Rite of the Catholic Church. It commemorates the finding by Saint Helena of the True Cross in Jerusalem in 355. The feast originally commemorated the dedication of the Basilica of the Resurrection and was linked with the finding of the cross shortly after.
Helena was reported to have found the True Cross on May 3, 355. However, most Catholic and Eastern Orthodox rites celebrate the Feast of the Cross on September 14, commemorating the day in 628 that the piece of the cross taken by the Persian Empire was recovered by the Byzantine Emperor Heraclius. After the Gallican and Latin Rites were combined, the days were observed individually as the Finding of the Holy Cross (May 3) and the Triumph of the Cross (September 14). Some Protestant churches followed this practice; the Church of England's Book of Common Prayer places Roodmas on May 3. However, the celebrations were combined into one feast by Pope John XXIII in 1960, and since then the Catholic Church uses only the September 14 date. The Church of England followed suit with the adoption of the Common Worship liturgy in 2000.