Radonitsa

Tomorrow, Tuesday of Thomas Week, is known as Radonitsa (roughly translated, the "Day of Joy") in the tradition of the Russian Orthodox Church, a day on which special prayer is offered for the repose of the faithfully departed. Here is how Radonitsa is described in the Synaxarion of the Lenten Triodion and Pentecostarion (a modern compilation):

On this day, the Tuesday of St. Thomas week, according to the order instituted by our Holy Fathers, we call to remembrance, in Paschal joy, all those who have died from the beginning of the ages in faith and in the hope of resurrection and life eternal.

Having previously celebrated the radiant feast of Christ's glorious Resurrection, the faithful commemorate the dead today with the pious intent to share the great joy of this Pascha feast with those who have departed this life in the hope of their own resurrection. This is the same blessed joy with which the dead heard our Lord announce His victory over death when He descended into Hades, thus leading forth by the hand the righteous souls of the Old Covenant into Paradise. This is the same unhoped-for joy the Holy Myrrhbearing Women experienced when discovering the empty tomb and the undisturbed grave clothes. In addition, this is the same bright joy the Holy Apostles encountered in the Upper Room where Christ appeared though the doors were closed. In short, this feast is a kindred joy, to celebrate the luminous Resurrection with our Orthodox forefathers who have fallen asleep.

There is evidence of the commemoration of the dead today in the writings of the Church Fathers. St. John Chrysostom mentions the commemoration of the dead performed on Tuesday of St. Thomas week in his "Homily on the Cemetery and the Cross."

Today, the faithful departed are remembered in Divine Liturgies, "koliva" is prepared and blessed in the churches in memory of those who have fallen asleep, and the Orthodox graves in cemeteries are blessed by the priests and visited by the faithful. On this day alms are given to the poor. Furthermore, it should be noted that due to the great spiritual joy this jubilant commemoration bears, it is called in the Slavonic tongue, "Radonitsa," or Day of Rejoicing.

There is no mention of a special commemoration of the departed on this day in either the Pentecostarion or the Typikon. Radonitsa is a specifically Slavic tradition (albeit with roots in deep antiquity) not observed by other national traditions (it's even a civil holiday in Belarus). It arose most likely because the Typikon specifically forbids the serving of memorial services from Pascha until Thomas Sunday, making Monday the first day on which the reposed may be formally commemorated. While S. V. Bulgakov mentions Radonitsa as having been celebrated on either Monday or Tuesday of Thomas Week, it is now always marked on Tuesday. (This is most likely because Monday is a fasting day in many monasteries, being the day on which the Angelic orders are commemorated weekly, which would prevent monks from partaking of the festive foods blessed). While there is no special commemoration of the departed in the liturgical services, it is cutomary for a general panikhida to be served in church and for litias for the reposed (a sort of abbreivated panikhida) to be served, accompanied by the singing of the Paschal Canon, at cemetaries and gravesites. (You haven't truly experienced the Paschal Canon until you've chanted it in a cemetary.) It is also customary to bless kutia or kolyva as well as some other special foods, to clean and decorate the graves of loved ones, and to give alms in memory of the departed. Radonitsa also begins the marriage season (marriages being forbidden during fasting periods). May the buyer beware!

For more, see S. V. Bulgakov's handy Handbook; a good explanation by Gregory Orloff of both the theological basis of this commemoration, as well as a description of folk customs, can be found here; the relevant Wiki entry is here; this article, while not written specifically for Radonitsa, provides a sort of "how to" for participation in memorial commemorations; for two brief articles on why we pray for the departed at all, see here and here; those who can read Russian will want also to consult this article for practical guidance on how to mark this day. For a sermon on Radonitsa given by Archimandrite Tikhon (Shevkunov), go here.