I'm in the US... in my company they have a variety of schedules available to choose from. Initially, the core hours are 0900-1500 for training, so as long as you are here for those times, you can flex around it. Still have to work 8.5 hours (with 1/2 hour for lunch) a day, but those can start as early as 0700 so you can leave at 3:30pm, or as late as 0845 and leave at 5:15pm. Once you are no longer in training, you can flex with arriving time from 0600-0900 and then leave from 3:30-5:30pm, again, as long as you put in 8.5 hours for the day. Then we have a compressed work tour, which is what I work. You can't flex your time (it's a set schedule) but you get a day off every 2 weeks. I work 8 9hour days, 1 8 hour day, and get a day off for a total of 80 hours worked every 2 weeks. So I start work at 0730 and leave at 5:00pm, with a half-hour for lunch. Technically, we work 8 hours a day and get a half-hour for lunch, so we work 40 hours each week but are in the office for 42.5 hours per week if you include the lunches.
I like the compressed tour, because I get a day to do my errands, appts, etc that I normally would be trying to take leave for, so it let's my leave get saved for more fun stuff, I can still go get my nails/hair/etc done, and still have all the family time I want to have. Oh, and I get to sleep in on that day too, which is really nice.

With two little boys, that sleep is sometimes the most important thing I give myself on my down day.
Is there/was there ever really a 9-5 job, with an hour lunch??? Did they really pay you for 40 hours a week, or only 35? And if 35 was a normal work-week, when and how did it get bumped up to 40 for a standard? Questions that have haunted me for a lot of my work-life.