Bright Week (or Renewal Week; in Greek, Diakaimsimos) is the first week following the Resurrection of Our Lord and Savior Jesus Christ, which is celebrated each year at Pascha. It ends the following Sunday, the Sunday of St. Thomas. For Orthodox Christians Bright Week begins a period of celebration that continues for fifty days until Pentecost.
This celebration includes the practice of the faithful joyously greeting each other with the salutation of Christ is risen, followed by the response indeed He is risen or truly He is risen, as the whole of creation is renewed by Our Lord and Savior. The services of Bright Week are done with the Royal Doors fully open. This unblocked view of the altar symbolizes the open door of Christ's empty tomb as well as the rent veil of the Jewish Temple, which was torn apart at the moment Christ died. Also, fasting is completely prohibited to all Orthodox during Bright Week so that the faithful may recover their strength after the eight weeks of Great Lent and Holy Week.
It is also an unwritten orthodox rule that the god-sibling of a newly illumined christian gets to treat him to lunch during Bright Week.