[notahacker]

If you fly to Madrid and look at your phone you're still going to need that massive table of local custom by region, or you're going to be utterly baffled when most shops start closing at 13:30 and then reopen in early evening, and the restaurants are all closed at 18:00.

There's no shortage of international differences in opening hours, days and times and time-zones don't really get you very far towards understanding them.

[philwelch]

But I would have to know that about Madrid either way. It would at least help to know when those times are relative to the local day cycle.

Time zones give me a few bits of information and knowing about local customs gives me the other bits, but the bits that are encoded in the time zone are bits I can ignore as soon as I change my clock, just as setting your zero helps you work out a physics problem. Instead you want me to worry about all the bits all the time. Why, to make it easier for computers? I thought computers were better than me at handling bits.