It has always seemed pretty acurate and seen it used many times . here is the Us version , Can you say COLLAPSE ? http://www.usdebtclock.org/there is a difference between a debt and a budget surplus.
You can have both at once.
Debtclock seems to be an anonymously owned & run site with no reference to where it gets its figures from - you can mouse-over the numbers and it gives a little definition - but not the source of the actual data. Until you can establish the bona fides of its info I don't think it can be considered reliable.