Comment on Why don't we have one timezone covering the whole earth?
captainjaneway@lemmy.world 9 months agoIt’s not that different. But you’re mentally mapping a UTC offset to your local time as well? Doesn’t that mean you have to do something like:
- Does this time work for me? (Map offset to my time)
- Does this time work for them? (Map offset to their time)
Genuine question here. Seems like you’re doing twice the time-conversions when using UTC.
XeroxCool@lemmy.world 9 months ago
If UTC is being used, I’m only converting once. If a time is given in UTC, I only need to convert to my time. If I’m looking for a time at some place (and not just looking it up directly) then I’d combine the absolute values of the offsets before doing a time conversion. I wouldn’t say my 9am is 2pm UTC and 2pm UTC is their 4pm, I’d just do my 9am is their (9+5+2=) 4pm.
Working with time zones makes it easier to keep times in your own perspective. You look up their offset and take a decent guess that their working hours match yours and you’d probably aim for something a little off from your start/end times and safely land towards the middle. To me, that sounds more reliable than hoping to find business hours posted without a distinct, clearly defined geographical divide in which you know the sun is going to shine there.
I suppose that’s where the “simplicity” really comes from in my above points: time zones give you tables of information about times elsewhere, UTC-only requires a map and interpretation. Would places refine their day time shifts narrower than an hour? A minute? A second? Look at the central time zone in the USA. Columbus, Georgia is EST at -5. Ladonia, Alabama is -6 in CST, just across the state border. 1000 miles away, Seminole TX is on the other border of CST and Lovington, New Mexico is across the border in MST at -7. With time zones, the whole region from TX to AL agrees what an 8am start time is, despite effectively being offset by a whole hour, celestially. But solar noon is only at 12 for people in the middle, at the east border of TX, 500 miles between the two city pairs above. So if everyone goes to UTC, how do you know what a place uses as their schedule? Would Marshall, TX, stay at -6 while the GA/AL pair use -5.5 and the TX/NM pair use +6.5? That 8am local start time would become 1pm UTC for Marshall, 1230utc for ga/al, and 130utc for tx/nm pairs. Would Dallas, between Marshall and Seminole, be -5.78 and start the work day at 01:46:48pm utc? Way harder to track. Hence, the railroads gave us time zones