The Church today commemorates Thomas Sunday, held exactly a week after Holy and Great Easter Sunday.
According to the Gospels, And Thomas, beholding and examining carefully the hands and side of the Master, cried out with faith, “My Lord and my God.” Thus he clearly proclaimed the two natures – human and divine – of the God-man (Luke 24:36-49; John 20:19-29).
This day is called Anti-Pascha, meaning “in the stead of Pascha,” and not “in opposition to Pascha”.
Pascha, from the word Passover, denotes Easter in Greek
The commemoration comes on the first Sunday after Pascha, as the Church consecrates every Sunday of the year to rejoice in Pascha, the Resurrection.