24 hour-ness
Haven't been to Toronto, so obviously can't comment on whether it is, or is not, a 24-hr. city. But the idea of a city's "24 hour-ness" has always fascinated me. So here are some observations about the "24-hour-ness" of New York City (which has been mentioned in other posts as a point of comparison) -- having been born and raised here (and having lived in Greenwich Village for 40+ years).
Two main thoughts:
1) It seems to me that the 24-hour-ness of cities can change over time, even without the physical city itself changing all that much.
When I first moved to the Village I was disappointed at how un-24-hour NYC turned out to be. Looking back, I suspect that by the late 1960s NYC had become a lot less 24-hour then it had once been (e.g., due to suburbanization, crime, etc.). Things seemed to get worse in the 1970s. But, now, NYC seems once again to have blossomed into a true 24-hour city.
For instance, just in Greenwich Village alone, in addition to the obvious "after hours" clubs, and 24-hour fast food franchises, etc., there is NYU's enormous 24-hour (for students and faculty only) library; a large 24-hour supermarket (see more below); a 24-hour laundromat; a 24-hour self-service storage facility; a 24-hour newspaper stand (although with the internet, who knows for how much longer); a large 24-hour chain store pharmacy; numerous 24-hour "Korean" grocery stores; a very late night haute cuisine restaurant that is an after hours hang-out for other restaurant workers. Until recently, when it was torn down for the construction of condos, there was a large, busy 24-hour gas station. And while I'm not sure if it is actually all-night, there is even a storefront place to play chess on Thompson Street that is open until the wee hours of the morning! (I think it was still open at about 2:00 or 3:00 a.m. when I've passed by.)
Twice last summer I had to get a 3:30 a.m. bus from the Port Authority bus terminal to Boston (there were also buses to Boston at 4:30 and 4:45 a.m.). Since I didn't want to take the subway that late at night (felt safer on the street), I walked -- and I was surprised at how crowded the streets were in an area that had once been something of a no-man's land between Greenwich Village (expectedly crowded) and Times Square (expectedly crowded). There were even a few food carts (actually trucks retro-fitted as food stands)! I thought the bus itself would be near empty, but there were so many people waiting that not everyone made it onto the 3:30 a.m. bus, and some had to wait for the 4:30 a.m. one.
And that's not to mention the other parts of town (that are still in Manhattan), and "hidden away" third shift workers (especially in the financial services industry which, due to trading being done in other time zones, has become more of a 24-hour industry).
Interesting to note, in the 1970s, the 24-hour supermarket in the Village that I mentioned was only open until 9:00 p.m. Plus banks, which were only open Monday through Friday, usually closed at 3:00 p.m., except for some that had sidewalk windows that were open until maybe 7:00 p.m. or so. (And, remember, in those days there were no ATMs, and credit cards were not as acceptable as they are today.)
2) I think in any city, the 24-hour-ness is not always going to be readily apparent. For instance, for years there has been a commercial bakery a few doors away from me, and only recently did I find out that it had a 3rd shift.