Londinii in Anglia, sancti Eduardi, cognomento Confessoris, qui, rex Anglorum populo suo propter eximiam caritatem dilectissimus, regno pace comparavit atque communionem cum sede Romana tenaciter promovit.
Well there we go. Silly me. I always thought his feast was in October. There's quite a lot of this arbitrary moving of feast days in the current martyrology, for no apparent reason. There can sometimes be a minor ancient feast (the translation, or reburial, for instance) but neither my Sarum calendar nor the Hereford calendar note it, today being simply the octave of St Thomas Becket. This shift is particularly puzzling as it isn't as if St Edward were a nobody: his feast was kept in the universal calendar (if only by way of commemoration) right until the 1969 reform.
For once the English and Welsh Episcopal conference have been sensible and continue to keep St Edward on his traditional day in October.