OT: Time Zones

[CycleChic06]

Can anyone explain to me this mystery? Why is India GMT +5.30 hrs? Where the heck does the extra half and hour come from??

[IFjane]

Good question! I wanna know, too - any time zone experts out there???

[jobob]

um ... I dunno ... the position of the sun?

Time zones in parts of Australia and other areas of Asia/Pacific, and Newfoundland, are 1/2 hour off as well.

Here's a great site to look up the local time anywhere:
http://www.timeanddate.com/

[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.

[IFjane]

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

gotta love flying over the international date line.

OMG. I have a hard enough time flying from coast-to-coast.....I can't imagine keeping up with whole days!

[light_sabe_r]

Can't explain where it comes from, All I know is SA is Half an hour ahead of QLD at the moment because of Daylight savings... and SA is WEST of Queensland.

>_< I feel sorry for the peeople of Coolangatta (gold coast QLD) and the Tweed (NSW)... You can basically cross the street and be in a different time zone at the moment.

[Duck on Wheels]

Russia covers, I think, five time zones, but the Transiberian Railway keeps Moscow time all the way to the Pacific. So if you live in, say, Irkutsk, you have one time outside the railway station and another time inside, and one time for Transsiberian train schedules and another for local trains. I guess it gives people something to work on mentally during the long, dreary Siberian winters.