GIGO: words unreadable aloud
Mishrogo Weedapeval


  Sunday 7 April 2002
DST Asymmetry Reminder

It's April: time for my annual reminder about the asymmetry of daylight savings time. If you've seen this before, well, here's a reminder.

The summary: Daylight Savings Time is not symmetrical around the solar calendar -- it does not "surround" the days of longest light as one might expect if one hasn't thought about it. So if you like to do outdoors stuff (e.g., hiking or mountain-bike riding) while it's light out, especially mid-week after work, the time to get started with that sort of outdoors stuff is NOW.

Some details: If we were to start DST at the spring equinox and end it at the autumn equinox, then it would be close to symmetric in the sense I'm talking about. Around the day we spring ahead into daylight savings time, sunset would change from being (say) 6:30 to being 7:30; and the day we fall back to winter time, it would go from 7:30 to 6:30. But we don't do the DST changes until some time after the equinoxes. We spring ahead in early April, roughly 11 to 18 days after the spring equinox, and we fall back in early October, somewhere around two weeks after the fall equinox. This means that it's lighter later into each day at the start of DST than it is at the end. In fact, a little bit of trigonometry (or some actual observation) will tell you that the equinoxes are the times of the fastest change in the days' lengths, so it's lighter a lot later at the start of DST than at the end.

Around here (San Francisco Bay Area), the springtime change this year made our notion of sunset change from 6:30pm to 7:30pm. So it's already worth getting out for a short (~90-minute) hike or ride after work even if you have to work until 6:00pm.

By contrast, the autumn change around here usually seems to make our label for "sunset-time" change from about 6:00pm to 5:00pm or so. That's an hour and a half difference, compared to the springtime change. It generally means that despite the usually dry autumn weather we get, those of us who have to work until 6:00pm or later have few choices by October -- learn to like riding with lights (and to find places where it's legal), or stick to riding or hiking only on weekends, "hookey" weekdays, or long "lunch"es.

Bottom line: For those of us for whom snow is not an issue, the dry parts of April are the time to start those after work hikes or rides (except for El Niño years, whose Aprils have no dry parts).
9:23:45 PM   comment/     

Mooseyard; and the Willie Fire

Phil says Moose rule my neighborhood. We had a family of moose (a mama and two "babies") in the common grounds at our Montana cabin a couple of years ago. Apparently this mama had wandered in to town that spring, and settled down on the lawn of the hospital to birth her twins. And they were back, browsing on the plantings of the park that summer when we were there. Born that spring, the "babies" were already seven-footers in August.

Willie Nelson came to town for a concert the first weekend we were there. Some idiot dropped his bike six miles south of town (on his way up Beartooth Pass) and started a big fire. The firefighters dubbed it "the Willie Fire". When my Irish friend first heard about it, his only comment was "... sounds painful!". The word "Willie" has additional connotations in the U.K. as compared with the U.S.
12:34:36 AM   comment/     

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