Liturgy:

Wednesday, January 29 - Festal Vespers at 7:00 pm. 

Thursday, January 30 -Divine Liturgy at 7:00 pm. 

The Three Holy Heearchs are Saint Basil the Great, Saint Gregory the  Theologian and Saint John Chrysostom.  Each of these three bishops have their own feast day. This combined feast day on January 30 was instituted in the eleventh century.  There was a  debate of which one of  these three bishops was the holiest.  The debate was settled by Bishop John of Euchaita (feast day June 14) after a vision where each of the three bishops appeared separately in glory and then all three appeared together.  The Holy Hierarchs said,  "We are one in God and there is nothing contradiction in us; neither is there a first or second among us." They then advised him to establish a common feast advised Bishop John to establish a common feast for them. 

Troparion for the Feast of the Three Holy Hierarchs

O teachers of the universe,  equal to the apostles, pray to the Lord of all to grant peace to the world and abundant mercy to our souls.