The miracle of the resurrection of Christ is witnessed by the blessed fire that lights up yearly on Easter night in the Jerusalem temple dedicated to the Resurrection of Christ. This temple was built by the empress Helen in the fourth century at the place of the burial and resurrection of our Savior. The origin of that fire is unexplainable. At the onset the blessed fire is cold and can be passed across one's face without burning. It gets to its normal temperature of fire only after some ten or fifteen minutes. The Orthodox Patriarch of Jerusalem (or his proxy) after having received the fire, lights other candles with it, and immediately gives them out to the believers gathered in the temple. It is remarkable that the blessed fire comes down only at Orthodox Easter. Representatives of other religions that serve the mass in that temple do not receive the fire.
Jewish Passover is celebrated on the 14th day of the lunar month of Nissan. That day always falls in spring at the full moon. Christian Easter is closely connected to the Jewish festival. The first Ecumenical Council, gathered in Nicea in the year 325, ordained that Christian Easter be celebrated on the Sunday at the time of the spring equinox, right after Jewish Passover. According to this ordinance of the Council and astronomic calculations, Alexandrian astronomers have developed a system to calculate the Christian Easter feast for every year. Thus, there appeared "Paschalia," the table of Easter's days for many years ahead. Alternation of the Paschal days repeats every 532 years (Indiction). According to the Paschalia, the earliest Christian Easter falls on the 22nd of March of the old-style calendar (on the 4th of April of the new-style). With Easter moving, the Great Fast, which depends on it, also moves. Thus, the celebrations of God's Passage to Jerusalem or Palm Sunday (a week before Easter), Ascension and Trinity (on the 50th day after Easter) also move with Easter. According to Paschalia, in 1999 Easter will occur on on the 11th of April; in 2000 on the 30st of April; in 2001 on the 15th of April; in 2002 on the 5th of May.