http://en.wikipedia.org/wiki/List_of_statutory_minimum_emplo...
The US has 0 (zero!) mandated days off. Even China gives people 5-15 days minimum.
Holidays and sick days are cumulative too, and you're entitled to be paid for untaken ones when you leave your job, so log as you've worked there a minimum of 1 year
A typical American gets 2 weeks of stat holidays on top of their 2 weeks of personal holidays, so that's almost the same as the European getting 4 weeks.
Currently I get 25 days per year not including 6 days stat, for 31 days total or just over 6 weeks total. This is considered average for London and the UK, I would consider 5 weeks to be the absolute low end in the UK. At the upper end in London the news about the Tube Drivers strike disclosed that they have 40+ days holiday, which is just over 8 weeks.
When I lived in Sweden the numbers were higher, with it being compulsory to take a fortnight in a contiguous block in the summer. The UK is the worst of the lot, and we have it OK.
Just my experience, but it varies so greatly from what you're quoting that I felt obliged to respond.
I can't wait for the day all trains are auto pilot.
(Again, this varies. In Germany it is usually around 28-30, in Spain around 22)