The holiday is in observance of Whit Monday, so most major players in Europe will be out. London will be open though, so there is still that at least. But even with major markets in the region being open, liquidity should be thinned out in the session ahead. France, Germany, and Switzerland are all enjoying the long weekend.
As such, there won't be any major data releases in the session ahead. That will make for a quieter period in European morning trade to start the new week.