The Fortieth Day, and Why It Is Always a Thursday

Ascension Day marks the withdrawal of the risen Christ into heaven, narrated at the close of Luke's Gospel and again at the opening of Acts, where it is placed forty days after the resurrection. Counting forty days forward from Easter, itself a movable feast tied to the paschal moon, fixes the Ascension always on a Thursday, between 30 April and 3 June. The number forty is scriptural shorthand for a complete span of preparation; the feast closes the "great fifty days" of Eastertide at its fortieth.

In the liturgy the paschal candle, burning since the Easter vigil as a sign of the risen Christ present among the disciples, is extinguished. The ten days that follow, between the Ascension and Pentecost, are days of waiting for the promised Spirit, and are the origin of the novena as a devotional form. Where the Thursday is no longer a civil holiday, many Catholic bishops' conferences have transferred the observance to the following Sunday, a move some liturgists criticise as erasing the deliberate arithmetic of the fortieth day.