Aren’t Good Friday and Christmas Day the only bank holidays that coincide with Christian holy days?
I suppose St Stephen’s (Boxing) Day could be added, though virtually every day is some Saint’s day, and Whit Monday could have been introduced in deference to Pentecost
Other than that New Year’s Day was introduced (in England) fairly recently due in the main to half the population phoning in with a hangover sicky; May Day is again fairly recent, introduced (I think) by one of Harold Wilson’s governments to commemorate ‘the workers’ ; and the August bank holiday presumably for no reason other than it would be nice to have a long weekend with the children before the schools go back
Personally I think November 5th should be a bank holiday 