Apparently (http://en.wikipedia.org/wiki/Time_zone) there is a time zone that is UTC -12 (Baker Island and Howland Island, both uninhabited) and another that is UTC +14 (Line Islands, part of Kiribati). Wikipedia says that since the UTC-12 islands are uninhabited the time zone is unspecified but we can go with this time zone anyway. Kiribati does not use daylight savings time, and I would venture that neither do Baker and Howland Islands. Since the international date line goes through the middle of a timezone ( http://en.wikipedia.org/wiki/International_Date_Line#/media/File:Internation...), it would seem that the "real world" maximum length of day is thus 50 hours. Cheers, Seb On 7 April 2015 at 21:35, Dan Asimov <asimov@msri.org> wrote:
I agree that if the simplest model I intended is not used, we can get all kinds of different answers.
The second part of my original question asked: What is the actual time that it is one actual day D at least somewhere on Earth?
For this question, let's assume just the time zones and International Date Line as they currently exist on Earth. (With no mention of Daylight Saving, leap seconds, precession, or nutation, etc.)
I do not know the answer to this question, but would like to know.
--Dan
On Apr 7, 2015, at 3:57 AM, Seb Perez-D <sbprzd+mathfun@gmail.com> wrote:
If you start in the first time-zone to be yyyy/mm/dd, at 0:00, and travel west at the same speed as the sun, you'll get to the last time-zone in 23 hours, with a local time of still 0:00. You can then spend 24 hours in that last time zone and will stop the chronometer with 47 hours, which agrees with Adam's answer.
However, if you choose your day carefully and time it with the move off daylight savings time, you can hope to get one hour more.
If DST is not allowed, then on a specific day we might win one UTC leap second (in line with the subject of this email), bringing the total to 47 hours and 1 second.
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