Now that's a day that deserves to be celebrated and go right over the top.
Sadly, aside from a few most of the country don't even recognise what day it is! - aside from your anniversary of course
I refer to St. George's Day. Sadly most English people know St Patrick's Day as March 17th - most of them celebrate it (I use the term loosely as most of them get bladdered).
Not sure if many English people even know 23rd April is St. George's day, let alone celebrate or commemorate it.