The states with some of the longest holidays (e.g. France (30 days per year), Germany (24 days per year)) are the economically strongest states in the EU. It's France and Germany that can afford to bail out the countries with less working time, e.g. Ireland (20 days), Greece (20 days), Portugal (22 days).
(for the record 20 days is the legal minimum under the European Working Time Directive)