SS Warrimoo, the Ship That Existed in Two Centuries at Once | Hacker News Reader

SS Warrimoo, the Ship That Existed in Two Centuries at Once

atlasobscura.com

20 pointspasswordoops13 comments

FTA, the ship crossed the international date line on December 31, 1899 so briefly the front of the ship was on Jan 1, 1900 while the back of the ship was still in Dec 31, 1899.

Both of these dates are still in the 19th century, however, so "two centuries at once" is wrong. The 20th century did not begin until Jan 1, 1901.

That's true in strict usage where there's no year 0 between 1BC and 1AD, but in popular usage years in the 19th century begin with 18 (i.e. from 1800 to 1899), and in astronomical year numbering 1BC is year 0, so the first century is 1BC to 99AD inclusive, and so on. This is also true in ISO 8601.

As a counterpoint, was the Y2K problem something that would have happened on January 1, 2001, or January 1, 2000?

Sometimes the common understanding of a century as being the years xx00 through xx99 is more relevant than the "technical" understanding.

The article covers that:

>And then, of course, there’s the matter of the new century. As some may remember from the whole Y2K hullaballoo, centuries (and millennia) only end when the year ending in zero is over, not when it starts. So, just like the 21st century and the third millennium started on January 1, 2001, the 20th century began on January 1, 1901, not 1900. (Not that this chronological truth got in the way of popular opinion.)

Time resolution is a funny thing. With enough detail, it can be said that your head exists in a slightly different time than the PC you are sitting at, or that one end of a RAM module has a slightly different time than the other end.

Fortunately we haven't yet reached situations where that would actually matter, and, with some luck, never will.

>While we were crossing the 180th meridian it was Sunday in the stern of the ship where my family were, and Tuesday in the bow where I was.

A difference of 2 days? How does that work? I thought it would just be a difference of 1 day.

Crossing the international date line is fun. On my first trip from Hawaii to New Zealand, we got to skip a Monday on the way there, and enjoy two Saturday nights on the way back.

I don't get it. Straddling any time zone boundary at midnight would have just the same effect, no?

At midnight on New Year's Eve on the boundary of a century, yes.

Yes, that's the exact scenario being described in the article. So I don't see why the IDL matters.

No, I don't think the IDL matters either.

Yet another fun story assaulted by pedantry.

I'm not sure I see a story without the pedantry. Or, perhaps, the only fun in this story is the pedantry?

(Sorry, should have prefaced this, "well actually"

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