This Thursday is Ascension Day, the festival commemorating Jesus’ return or “ascension” to heaven, and his enthronement there “at the right hand of God the Father Almighty”. Ascension Day is the 40th day of the Easter season, which always falls on the Thursday following the sixth Sunday of Easter. Like the date of Easter Sunday, then, the date of Ascension Day changes from year to year. Jesus’ ascension is described in Acts 1.1-11, and is either mentioned or alluded to in many other New Testament passages.
There is a sense in which Ascension Day is the “opposite” of Christmas Day. Christmas Day is the celebration of Jesus’ coming into the world, and Ascension Day is the celebration of his return to heaven. Together, these two events “bracket” Jesus’ life and ministry on earth. Even though his departure no doubt saddened his disciples and followers, Ascension Day is a joyful festival, since it celebrates Jesus’ return to his rightful position of power and authority in heaven. The symbolic color for Ascension Day is therefore white, signifying joy and celebration.