They also have to stock enough food for the full Irish breakfast - last year they served between 100 and 150 meals for breakfast.
This year they already had 85 bookings for the costumed breakfast, but were expecting even more people to "pop in".
"In the morning the crowd really get into it," the manager said. "We have an older crowd most of the time but on St Pat's they range from the very young to grandparents. It's amazing to watch. The grandparents are often the most dressed up."
After being at the pub for six years, Mr Brunskill said he found it amazing how much Kiwis got into St Patrick's, and thought it was the country's most celebrated day after Waitangi Day. "It shows everyone's a little bit Irish."
Police alcohol harm prevention officer Sergeant Raymond Wylie said police were expecting some premises to have one of their busier nights of the year, however every year premises were becoming better at managing their patrons. "Currently I have a great deal of confidence in our licensed premises and do not expect significant levels of rowdiness or disorder."
He said licensees and managers were well aware of their obligations and would be vigilant to intoxication and behaviour issues.
"Police are aware that St Patrick's Day will see an increase in patron numbers and vehicle movements and in response the general public can expect to see a police focus to these areas."