From the Church bulletin at St Andrew's in El Segundo
On the 12th of January, the Afterfeast of the Theophany, we commemorate the martyr Tatyana of Rome and those who suffered with her. Saint Tatyana was a Roman whose parents were from the nobility. She was a Christian and a deaconess in the church. The Emperor at that time, Alexander, , was wavering and indecisive in his faith, for he kept the statues of Christ. Apollo, Abraham, and Orpheus in his palace. His assistance took it upon themselves to persecute the Christians without waiting for orders from him. When they brought out the virgin Tatyana for torture, she prayed to God for her torturers. They behold four angels standing around the Saint, and eight of them fell to the ground and professed belief in Christ, for which they were also tortured and slain. Other tormentors continued their savagery on Tatyana or days, placing her in a dungeon each night. The next day, by God's grace, she appeared before them completely healed. Finally, Tatyana and her father were led out together and both were beheaded in about the year 225.
In Russia this is often known as day of the student (she's a patroness of students'). This is also my dad's birthday, as well as my cat's feast day :)