This must be a mistake on the calendar, no? In fact – no – Sunday really is a fasting day. Why? The eve of Theophany is always a fasting day – no matter what day of the week the eve of Theophany falls on. So yes – Sunday is in fact a Lenten day. Please take note, and please plan to join us that day for Liturgy, or Vigil in the evening for the feast of the Theophany, or even better: for both services! :)