4 June 2180, Sunday (21.05 according to the old style)

Pentecost. Holy Trinity Day

Saints commemorated

Equal-to-the-Apostles Constantine the Great, Equal-to-the-Apostles 272–337
Equal-to-the-Apostles Equal-to-the-Apostles Constantine and Helen IV век
Equal-to-the-Apostles Helena, Equal-to-the-Apostles ок. 250 – ок. 330
Right-believing Prince Constantine (Yaroslav Svyatoslavich) of Murom † 1129
Righteous Theodore of Ostrov (Oyat) XVI век