OT: Time Zones

[Duck on Wheels]

Uhmmmm, lessee if I remember from my Geography major 35 years ago. Time zones are a compromise between two kinds of precision, social and natural. Do we all want to agree on what time it is? Or do we want time to make sense in terms of the height of the sun, rotation of the planet etc. To agree on what time it is over decent chunks of geographical space, we've made these more or less arbitrary divisions into "hours". Why hours? Why 24? Why not 20? Or 50? or 11? Historians have discussed how this happened, but basically it was an arbitrary decision that worked well enough given the ways clocks had developed up to then and the speeds and distances folks travelled back when the decisions were made.

Back then there was political rivalry over where to start counting. Paris? London? Again, historians can tell you how it wound up being Greenwich, but whatever the specifics the decision was political, and in that sense arbitrary.

Why do the zone lines make zigs and zags? Why have some places added or subtracted half an hour? That has to do with local adjustments so that time in some politically important place or across some functional social area is uniform and matches reasonably well with the height of the sun. After all, dividing the circumfrence of the earth into 24 exactly equal and straight-edged sections starting at Greenwich would make for some strange situations, like an hour's difference between one side of a street and another, or even one side of the bed and another. So local adjustments have been made.

Does that make sense now? If so, then I'm probably remembering it correctly. If not, I'll have to go back and look it up.

[IFjane]

Thank you Duck - it does make sense - but I'm willing to bet, even with zig-zag lines and such there are still places where the time is an hour off on either side of the street! or meadow....or lake....

[Tuckervill]

It's how many hours you are, plus or minus, from Greenwich Mean Time.

Karen

[CycleChic06]

Uhmmmm, lessee if I remember from my Geography major 35 years ago. Time zones are a compromise between two kinds of precision, social and natural. Do we all want to agree on what time it is? Or do we want time to make sense in terms of the height of the sun, rotation of the planet etc. To agree on what time it is over decent chunks of geographical space, we've made these more or less arbitrary divisions into "hours". Why hours? Why 24? Why not 20? Or 50? or 11? Historians have discussed how this happened, but basically it was an arbitrary decision that worked well enough given the ways clocks had developed up to then and the speeds and distances folks travelled back when the decisions were made.

Back then there was political rivalry over where to start counting. Paris? London? Again, historians can tell you how it wound up being Greenwich, but whatever the specifics the decision was political, and in that sense arbitrary.

Why do the zone lines make zigs and zags? Why have some places added or subtracted half an hour? That has to do with local adjustments so that time in some politically important place or across some functional social area is uniform and matches reasonably well with the height of the sun. After all, dividing the circumfrence of the earth into 24 exactly equal and straight-edged sections starting at Greenwich would make for some strange situations, like an hour's difference between one side of a street and another, or even one side of the bed and another. So local adjustments have been made.

Does that make sense now? If so, then I'm probably remembering it correctly. If not, I'll have to go back and look it up.

Thanks Duck, that makes sense. I looked at a map of the world timezones and noticed that you are right, there are a few areas that are a half an hour off from everywhere else. It's also interesting that the ENTIRE Indian Subcontinent is in the same time zone and not divided up.

[Kitsune06]

...is it fair to still totally and completely hate the concept of time zones?

[chickwhorips]

what happens if you live and go to school on one side of a time zone and the other side is your work. which time zone do you follow?

[li10up]

If we didn't have time zones then at 10:00 am, for example, it would still be pitch dark in many places but broad daylight in others. I can't imagine a world without time zones.

[mtkitchn]

I'm flying to Sydney in March and will lose March 13th altogether. THAT is scary!!!

[chickwhorips]

i lost december 2nd last year, but had two dec 24th (or a really long one.)

gotta love flying over the international date line.

[Mr. Bloom]

what happens if you live and go to school on one side of a time zone and the other side is your work. which time zone do you follow?

This is very common in Indiana. I live in two different time zones between our two homes. Weekdays, I live and work in Eastern; weekends in central. I keep my watches, car clocks, and biological clock in eastern which means that I often fall asleep very early on the weekends.

Let's not forget, time is a man-made creation. Our reference points (the earth's rotation and solar orbit) don't change. It's inconvenient to straddle the line, but not the end of the world.

[Mr. Bloom]

Hey Silv...funny we were responding at the same time but in two different time zones!!

[crazycanuck]

K..whilst driving to melbourne last christmas we weren't aware that approximately half way into Western Australia there's a time change of 45 min. Then another time change when we hit the border with South Australia.

I still have no idea why..but then again this is Western Australia & a lot of things just don't make sense here..

Now if didn't have to stay up until midnight during the week to call my mom all would be cool.

Lovely time zones.

c