Alternate International Date Lines

The IDL runs more or less smoothly through the Pacific, the micro-reason being its scarce population and the macro-reason being European imperialism demanding an IDL running east of Australia and west of the Americas.

But what would it take to create a non-Pacific IDL or even an IDL running through continents?
 

ninebucks

Banned
The mid-Pacific is clearly the only practical place to put the dateline, as aside from a few isolated island-nations, the Pacific is basically uninhabited from the Bering Straits southward.

The Atlantic, the world's other north-south running ocean, is actually more S-shaped, so you can't draw a straight line down it without skimming way too close to any Atlantic nation.

Anyway, I would dispute your claim that the placing of the OTL dateline had anything to do with Western Imperialism, even if the world's dominant civilisations had emerged in Eastern Asia and Western America, the dateline would still be mid-Pacific, because thats the best place to put it!
 
The mid-Pacific is clearly the only practical place to put the dateline, as aside from a few isolated island-nations, the Pacific is basically uninhabited from the Bering Straits southward.

The Atlantic, the world's other north-south running ocean, is actually more S-shaped, so you can't draw a straight line down it without skimming way too close to any Atlantic nation.

Anyway, I would dispute your claim that the placing of the OTL dateline had anything to do with Western Imperialism, even if the world's dominant civilisations had emerged in Eastern Asia and Western America, the dateline would still be mid-Pacific, because thats the best place to put it!

Ummm.... Except that the International Dateline is at 180 degrees - antipodal from Greenwich. If the 0 degree line (the prime meridian) had been elsewhere (through Germany, say) then the 180 line would be elsewhere. It's POSSIBLE that the dateline could have been kludged to 160 East or something, but that's... inelegant. Whatever happened, I don't imagine they'd move the prime meridian.

And I doubt highly that the location of the Dateline played any role at all in the original selection of the Prime Meridian. I suspect strongly that it's mostly LUCK that the Dateline goes through ocean.
 
@ ninebucks

Well, there is a precedent with the Philippines that used to be 8 hours behind Acapulco rather than 16 hours forward until the mid-19th century when economic activity had sensibly removed to local East Asia.

Why would it then be plausible to assume a Pacific-dominated world not to have a Kyoto Mean Time and an IDL through Greenland and St. Helena?


@ Dathi

So you assume that an Indian worldpower would be more necessary for an IDL in the Rocky mountains than to have the Japanese colonize California?
 
There was a time when there were competing prime meridians(British, French, German). Were there multiple IDLs?
At the time of competing prime meridians, i.e. before the Greenwich meridian was adopted by international agreement in the late 19th century, the concept of the IDL wasn't even thought of. The concept of an IDL was part and parcel of the time zone system, which was originally devised by the rail road industry here in the US in the 1880s. The IDL wasn't created until the time zone system was extended to the rest of the world later on.
 
At the time of competing prime meridians, i.e. before the Greenwich meridian was adopted by international agreement in the late 19th century, the concept of the IDL wasn't even thought of. The concept of an IDL was part and parcel of the time zone system, which was originally devised by the rail road industry here in the US in the 1880s. The IDL wasn't created until the time zone system was extended to the rest of the world later on.



Ok, but I'd think there must have been an informal division of dates.

It was devised in Canada actually.
 
One other option for the IDL would be the middle of the Atlantic, running between Greenland and Iceland. There are actually far fewer islands in the Atlantic than the Pacific so a straighter line would have been an option.
 
There is a Reason that the 0o line goes thru Greenwich [British] Naval Observitory

Yes, IIRC the French and the British had one of their fights over who could claim the Meridian. I think for a time, there was even two meridians. Nevertheless, the French relinquished their claim in return for some British colony somewhere.
 
The Prime Meridian is not the International Date Line. Paris and London sparred over who got the Prime Meridian because it was prestigious. Have the IDL run through one's country would be rather annoying, since it would be a different day on one side of it.

An Atlantic IDL might be possible, but it becomes awkward for translatlantic trade, especially given how close South American and Africa are. The best possibility is some variant of Zheng He discovers the New World, in which China dominates at least culturally so a "Middle Kingdom" map is adopted, with China at the Prime Meridian and the Atlantic as the IDL/Antipodes.
 
The Prime Meridian is not the International Date Line. Paris and London sparred over who got the Prime Meridian because it was prestigious. Have the IDL run through one's country would be rather annoying, since it would be a different day on one side of it.

Well, of course. But are you trying to claim they aren't intimately connected? I'd like to see you defend that!
 
At the time of competing prime meridians, i.e. before the Greenwich meridian was adopted by international agreement in the late 19th century, the concept of the IDL wasn't even thought of. The concept of an IDL was part and parcel of the time zone system, which was originally devised by the rail road industry here in the US in the 1880s. The IDL wasn't created until the time zone system was extended to the rest of the world later on.
In Britain it occurred earlier because of an earlier adoption of the railway. Before then towns were on local time and cities such as Bristol and Dublin were quire literally in different time zones.

Incidentally, the railways were also instrumental in standardising units of measurement. The North inch was different in length to the South inch.
 
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