So – time zones are simple. In the continental United States, there are four: Pacific Standard Time, Mountain Standard Time, Central Standard Time and Eastern Standard Time. Each an hour a part. The goal is to have all of us have a relatively normal ‘day’. With the sun rising at a reasonable hour, and the sun setting at a reasonable hour. Of course these don’t quite work. Boston (and especially the Cape) should really be in the next time zone over – but it is more convenient for them to be on the same time zone as the rest of the east coast. As a result – at the beginning of summer – the sun comes up about 4:00am.
But then – we got Daylight Saving Time. This meant that each spring, we set the clock forward an hour (spring forward), and then return the time in the fall (fall back). (This made the official sunrise on June 20th this year be a ‘reasonable’ 5:07am). The goal was to save energy – since much of our energy consumption is in the evening. If we made more of the evening be light outside – then we wouldn’t use as much electricity (See the Wikipedia entry for history – it ties the idea back to ancient Rome, to Ben Franklin, to a first failed experiment in the US during World War I, and then the beginning of adoption in World War II Time) See this page on the State of California’s web site, which references a study that showed that using Daylight Saving Time reduced the daily consumption of electricity is trimmed 1 percent.
So you now have Pacific Daylight Time, Mountain Daylight Time, Central Daylight Time and Eastern Daylight Time.
In the 1950s, the railroads didn’t use Daylight Saving Time. I grew up in Barstow, California. Barstow had the largest railroad switching yards west of Chicago. My baby sitter’s husband worked for the railroad. So in their house, the clocks all were set to Pacific Standard time all year. This added to a kindergartener’s confusion as I learned to tell time (and for you kids - this was when clocks had hands - none of this digital stuff).
But wait – there’s more. Arizona decided not to honor Daylight Saving Time. So Arizona stays on Mountain Standard Time through the suumer – which then matches Pacific Daylight Time.
Ah – but just when you understand that – and you are traveling on vacation through Arizona – you discover that the Navajo Nation (which is a large part of Arizona) does do Daylight Saving Time. And the National Monuments in Arizona (like Canyon de Chelly) run on Mountain Daylight Time.
I have gotten used to my cell phone/organizer (now an iPhone) handling time for me. It is set so that when I get off a plane in some random city, it syncs with the cell network, and shows the local time. On our recent trip, this has failed miserably. Nevada is PDT, Idaho is MDT, but at one point while in Nevada – I must have picked up an Idaho cell network – and phone shifted to MDT. And much of the time in Arizona I found my phone off by an hour (sometimes one direction, sometimes the other).
For many purposes on vacation – none of this matters. But knowing when things open and close (like the coffee shop, for example) can be quite crucial.
Managing systems that work across time zones – and had to work through Daylight Saving Time shifts is a challenge. Are there two 2:00AMs on a given day? Is 2:00AM before 1:30AM? Does the user want to see it in the vehicle’s time (at Sapias we tracked fleets of trucks), or the viewer’s time? As I was writing this - I was prepared to describe how Indiana has ny number of different ways of recognizing Daylight Saving Time (or not…) - but I discovered that a couple of years ago they fixed this. All of Indiana now honors Daylight Saving Time.
Mary and I always choose on the spring forward or fall back day - when we want to take advantage of - or lose - our hour. That works fine as long as we don’t have appointments on Sunday. And I need to make sure I am never in Arizona - and especially not in the Navajo Nation on either of those days - it would be too much to cope with.
Jim on August 14th 2007 in Travel, Technologies