Μεγάλη Τετάρτη, "της αλειψάσης τον Κύριον μύρω - Τροπάριο της Κασσιανής"
Sorry, we don't yet know the date of the next celebration of Great and Holy Wednesday.
The feast of Great and Holy Wednesday, "of her who anointed the Lord with myrrh - the Hymn of Kassia" is a moveable feast celebrated on different dates each year. Here are the latest known celebrations:
Fast
complete fasting day (nisteia)