CJ points us to the Ascension on June 1, 2011.  I googled this date,
and found disagreement on when it is.  A Catholic Church site says
it is June 3, but it's often celebrated on the following Sunday, the 5th.
And tying it to a certain number of days before Pentecost raises the
issue that we are not sure when Pentecost is.  

Here, again, we do not know the proper date of a "feast"!

Perhaps the Lord is again telling that we may know the season but
not the day or the hour.

Seek the season.

Mariel