[rue]

Indeed. It can also be explained as a matter of simple efficiency: Currently when synchronising something, two pieces of information must be known (the time, and the timezone). If using a single timezone, only one is required (whether it's night or day at either end is inconsequential, only the party at that end really needs to worry about it and can provide a range of hours suitable to them).

[rottencupcakes]

This is absolutely incorrect. Except in the singular example of arranging telecommunication across timezones, you have to maintain MORE information under this system. When I currently travel, I can make the assumption that any restaurant will be open by 11 AM, that I have to check out of my hotel by 11 AM and that I can't check in until 3 PM.

In your system, standard store hours have become a random regional fluctuation instead of a strictly maintained standard. I still need to maintain timezone information, but I ALSO need to do math in my head to figure out if it is an appropriate time to go to a certain kind of store.

[rue]

I don't know which of us is “correct”, but I disagree with your opinion on the matter.

You're making an assumption of a standard time of day when stuff's open (I agree, 11:00 is a reasonable assumption). I can, however, make that same assumption. In your travel model, the traveler must know the timezone (and work with assumptions from there). In my mode, the traveler would need to know the “standard daytime hour” and work with assumptions from there.

So, both require one piece of info when traveling, but a single timezone wins out when synchronising.

[salvadors]

You obviously don't travel much.

There is huge variation in these sorts of things worldwide. See, for example, http://www.spanish-town-guides.com/Opening_Hours.htm

[ghshephard]

Which of the three isn't (generally) true all over the world:

  o Restaurants open at 11:00 AM.
  o You check out of your hotel no earlier than 11:00 AM 
  o You can check in at 3:00 PM.

Certainly different hotels allow things like Early Checkin (I've checked in as early as 8:00 AM in hotels with a lot of vacancy), and late checkout (most hotels will let you check out at 12:00, and for a small fee, 1:00 is usually no problem). And yes, there are lots of restaurants that only do dinners, or breakfasts/lunches - but for a restaurant that does two shifts - 11:00 AM is usually a guaranteed time for it being open.

But, I don't think I've ever been to a country where the checkin/checkout/restaurant opening wasn't generally true.

Admittedly, I haven't been to the "One Time Zone China" - that might throw my theory out the door...

[salvadors]

Pretty much none of those are generally true across Europe.

Restaurant opening hours vary dramatically by country, largely due people tending to eat at very different times in different countries. To pick a restaurant I walked past yesterday: http://www.restaurant-thierry.fr/index.php?p=contact — open 12pm–3pm and 7pm–11pm. From my experience here those lunchtime hours are fairly common, although more restaurants would open earlier than than in the evening (unlike Spain, where lots of restaurants don't open until at least 9pm or 10pm at night).

On the assumption that #2 is "no later than", then where there's consistency at all it would be noon, rather than 11am.

Check-in has almost no consistency at all. I'm currently in France, and lots of the hotels I've been looking at have a 6pm earliest check-in. Many others are noon or 1pm. I haven't seen one yet that's 3pm.

[georgieporgie]

That's a cultural issue, and Spain has only one time zone anyway. A lot of business can be conducted across the United States, which is fairly consistent in its hours. I suspect that Russia is fairly consistent within their borders as well.

[salvadors]

The cultural issue is the entire point here, so it can't really be brushed away. The idea that pretty much any list of things could be true worldwide falls down rather quickly.

(PS Spain has multiple timezones: http://www.timeanddate.com/worldclock/city.html?n=141 vs http://www.timeanddate.com/worldclock/city.html?n=683 for example)

[jarek]

When you travel, how do you know what time it is?

Either way, you have to adjust something. Right now, you adjust your known time difference (i.e., change the clock, either by knowing the difference or by asking someone local). With that proposal, you would adjust the known opening times.

[anigbrowl]

With a single timezone then you need to know the longitude of the remote location instead. There's a book (called Longitude, unsurprisingly) about the piecewise invention of accurate chronometry in order to solve the problem of knowing your longitude at sea. Latitude you can work out pretty easily as long as you have an almanac, compass, and a protractor, but longitude is a problems sans clocks and logs of distance traveled.