What is "Ascension Day" and why were some Christians celebrating on May 9?
The Bible is not generally very precise about the days on which things happened (with exceptions like Passover, Good Friday, and Easter.) But the Church has chosen dates on which to remember the significant events of church history, even if they're not Biblical. May 9th of this year was "Ascension Day" (or Analepsis by the Orthodox Churches) - the day to remember Jesus's ascension into heaven after his resurrection.
The Feast of the Ascension, also known as Ascension Thursday, Holy Thursday (only by some denominations; not to be confused with Thursday of Holy Week), or Ascension Day, commemorates the bodily Ascension of Jesus into heaven. It is one of the ecumenical feasts (i.e., universally celebrated) of Christian churches, ranking with the feasts of the Passion, of Easter, and Pentecost. In the Roman Catholic church it is also known as the Solemnity of the Ascension of the Lord. Ascension Day is traditionally celebrated on a Thursday, the fortieth day of Easter (following the count given in Acts 1:3), although some Roman Catholic provinces have moved the observance to the following Sunday.So why didn't our church have a "feast" on this day? (I know some of you were feeling extra hungry!) Because many Protestant - and especially Evangelical - churches choose to only celebrate the major, Biblical, holidays. We go back only to the Bible.
That being said, if you want to celebrate, some churches celebrate as late as June 3! Traditionally, it is commemorated by an All-Night Vigil (i.e. stay up late praying and singing hymns) followed by Communion, then various traditional actions like marking the boundaries of a church's influence, and then finally with a meal. Enjoy!