RADONITSA - ("Day of Rejoicing", Krasnaya Gorka ) is a holiday in the Orthodox Church which falls on the Monday or (more commonly) Tuesday of Saint Thomas Week - eight or nine days, respectively, after Pascha (Easter). The day is a general memorial for the departed.
Because of the importance of the last few days of Holy Week and the joy of the Resurrection, the Typikon (Ustav) forbids the celebration of the Panikhida (memorial service) from Great and Holy Thursday through Thomas Sunday (a period of eleven days). Therefore, the first opportunity after Pascha to remember the dead is on the second Monday of Pascha. However, because in Orthodox countries a number of monasteries follow the custom of fasting on Mondays, the feast is often celebrated on Tuesday, so that all may partake of the paschal foods (which are intentionally non-fasting).
Today, in many local parishes, or where it is hard for families to gather at the graves of departed family on weekdays, graves are blessed on the weekend of Thomas Sunday.