For CPAs, St. Patrick's Day is usually just one of several holidays that becomes a casualty of busy season. On Presidents' Day we were unable to engage in parliamentary procedure, on Mardi Gras we are unable to get laid, and on Valentine's Day we are unable to get laid1.
Proper observance of St. Patrick's Day requires three components: a spiritual component, a green component, and a drunken component–all of which will be easier to do this year because St. Patrick's Day falls on a Sunday. (You're not officially required to work on Sundays, but you're unofficially expected to work on Sundays. Add St. Patrick's Day, and you've pretty much got a free pass to dick around. At work.)