today is not ordinary time

Today is the second Sunday of Easter.

Today is the octave of the first Sunday of Easter, usually called itself, Easter.

In the past today has been called Low Sunday in contrast to the celebration of the first Sunday of Easter.

Is has also been called Missa in Albis, Mass in White. The neophytes would join the assembly in their baptismal garments, in remembrance of their baptism at the Vigil. In England, that was spoken as Whitsun, and the time as Whitsuntide.