My DOT post of 20 Nov 2005 supporting Central time for Indiana

Title: Time Zone Boundaries in the State of Indiana
Docket: OST-2005-22114
RIN 2105-AD53
FR Refence Number: 70 FR 48460

To: Joanne Petrie
via "http://dms.dot.gov/submit/"
Office of the General Counsel (C-50)
400 7TH ST SW
WASHINGTON DC 20590-0001

PETITION FAVORING CENTRAL TIME (time zone width implications)
The nominal width of each of the 24 standard time zones is 15 degrees. This convention was adopted at the International Meridian Conference in Washington, DC in October 1884 (http://wwp.greenwichmeantime.com/info/conference.htm). Based on the initial meridian being at Greenwich, the nominal boundary between the Eastern and Central zones falls about midway east-to-west across Ohio, and down the eastern borders of Michigan and Kentucky. It's pretty obvious which Indiana border lies closer to that. Yes, there would be some pain at one border or the other if our whole state were on a single time zone, but there's clearly more to the choice than just flipping a coin.

The largely unstated implication of 24 one-hour time zones is that most people are willing to tolerate setting their clocks to a standard time that differs a maximum of +/- 30 minutes from their Local Mean Time (LMT), for the convenience of commerce (mainly the railroads in 1884).

If most people were willing to tolerate a 30-to-60-minute difference between their local time and their clock time, then 12 two-hour standard zones would have worked just as well. Continuing the thought, if willing to tolerate a 60-to-90-minute deviation, then 8 three-hour zones would have worked out fine. Likewise, if most people were willing to tolerate a 90-to-120-minute offset between local and clock time, then 6 four-hour zones would have been acceptable.

But, the fact that we got 24 one-hour zones implies to me that the consensus then was that a deviation of more than 30 minutes was unacceptable to the average person. I think this largely still applies today, which is at least partly why we see all of the grassroots support for Central time, now that we'll be observing Daylight Time. We were effectively already on Central time from April through October anyway.

Now let's look at the deviation between local time and clock time for Indiana under the two options for a single time zone for the entire state. On Central time, the offset between local time and clock time is only ten minutes for Terre Haute and 20 minutes for Richmond, both well under the 30-minute standard for a system of 24 one-hour zones.

On Eastern time, the offset between clock time and local time for Terre Haute is 50 minutes in the winter. During the 7 or 8 months of Daylight Saving Time, the offset between local time and clock time for Terre Haute is 110 minutes. If everyone in the continental U.S. were willing to tolerate having their clocks off by 110 minutes from their local time, we could have a single time zone from Maine to California, with everyone's clock set to the local time for Sioux City, Iowa.

Can you imagine the howls from Los Angeles and New York City with a system like that? And yet, both cities would have their clocks set only about +/- 90 minutes from their own local time, less than Terre Haute is being asked to put up with for over half the year, beginning April 2006, if most of Indiana remains on Eastern time.

Sincerely, Bill Starr
Bartholomew County resident
http://tinyurl.com/88nnw
Sun, 20 Nov 2005