In the UK I'm 9am to 5pm, however my contract allows for unpaid overtime. Usually management are pretty good with this though, and give some unofficial time off in lieu if I have to work OT.
Unless i was in serious financial trouble, or in a learning situation, i would never accept a contract that "allows for unpaid overtime".
Most of the companies i know don't allow for "paid free time", so why should i give away my time for free to increase profits for the company ?
The exception to this is of course "job salary", but i never accept those either unless i have a say in what exactly makes up the "job" part, and i usually tell the employer that "job salary" goes both ways, so if i'm done with my job Wednesday afternoon, i'll say "enjoy your weekend" and be back next monday. That's when we usually agree on paid overtime :)
At least in the UK the law specifically forbids working more than 48 hours a week, so it's pretty common to see contracts where you opt out of this regulation. Not because the company even intends to make you work overtime, but because if you happened to work more, even entirely out of your own free will, you could still sue the company for working more than 48 hours in a week. So it's a very common thing to add in contracts here.