The date is unknown. It is quite possible that William was never canonized as the official canonization process was not in place at the time of his death. He could have been elevated to sainthood by popular acclamation and approval of a local bishop.
Pope Alexander III - William is not included in the list of saints canonized by Pope Alexander III nor does the Patron Saint Index list a canonization date for him.
William is a saint but not a patron saint unless your name happens to be William.
William of Bourges is not a patron saint.
As per the Patron Saint Index, William of York is a saint but not currently a patron saint.
There are many saints named William so you need to be more specific.William is not a patron saint.
Saint Thomas More, Saint Clotilde & Saint William of Rochester are the Patron Saints of Adoption. Interestingly, Saint William of Rochester is solely dedicated to the patronage of Adopted Children, and no other areas of life. St. Joseph is the patron saint of families.
Liam is Gaelic for William. So, technically, St. William (patron saint of York England) is St Liam
The Patron Saint Inex lists no patron saints of bears.
Saint Lillian is not a patron saint as per the Patron Saint Index.
As per the Patron Saint Index, there is no patron saint of wrestlers. However, Saint Sebastian is the patron saint of all athletics and athletes.
A patron saint is supposed to be a protector in the Catholic religion. Patron Saint Angelico is the patron saint of artists. A patron saint is a protector of life.
As per the Patron Saint Index, Saint Cedd is not a patron saint at this time.
Saint David is not a patron saint of England. He is the patron saint of Wales.