[tz] Theory - proposal to delete the reference to population

Paul Goyette pgoyette at juniper.net
Fri May 18 23:46:00 UTC 2012

Do we get a royalty every time someone instantiates a new clock?


> -----Original Message-----
> From: tz-bounces at iana.org [mailto:tz-bounces at iana.org] On Behalf Of
> David Braverman
> Sent: Friday, May 18, 2012 2:23 PM
> To: tz at iana.org
> Subject: Re: [tz] Theory - proposal to delete the reference to
> population
> > How is time offset observation enforced?
> The Time Zone Police, naturally. I think they're headquartered on Cape
> Cod.
> You know, having followed this thread intently for the last couple of
> days, I think we might be onto something. Clearly the tzinfo database
> needs to reflect the wall-clock time of every clock on the planet.
> Just glancing around my office, I count at least ten clocks, with
> offsets ranging from UTC+00:00:05 to UTC-05:02:10. Some of these clocks
> are on servers and use some approximation of UTC (it changes as the
> BIOS clocks lose or gain time over time), some are on laptops at UTC-
> 05:something, and there's an antique clock permanently stuck at 7:03.
> (Or 19:03...I can't tell.) Of course, the servers and laptops
> occasionally reach out to NTP servers, so I'll have to capture exactly
> when they do this to make sure tzinfo maintains an accurate history. If
> someone would volunteer to go through all the system logs, we can
> probably piece together some of it, but unfortunately some of the logs
> have been overwritten.
> This logically requires substantial updates to the gazetteer. As I'm on
> the third floor of this building, we'll have to expand the
> locales/places/areas list to three dimensions. Oh--and my servers are
> stacked up five in a rack, so right there we've got five new time zones
> overlaying one square meter of Chicago.
> I almost forgot, I'm wearing a wristwatch, and I have a mobile phone,
> two digital cameras, and a handheld GPS receiver, all of which have (or
> are) clocks of some sort. We can ignore the GPS receiver, since GPS is
> pretty much the most accurate clock generally available. But still, I'm
> excited by the possibilities of creating a new zone for each of the
> mobile devices. Especially the wristwatches. We'll need to get everyone
> on the planet a notebook to write down when they adjust their watches,
> else the database just won't be complete.
> But how will we represent the watches/mobile phones/cameras moving
> through space? I'll be on an airplane tomorrow, traveling from the
> America/Chicago zone to America/Los_Angeles. I usually change my watch
> after takeoff. So we'll need to find some way to represent when that
> happens, because obviously that creates a new time zone right in seat
> 9F. I'll explain this to the flight attendants so all 150 of us can
> change at the same time, just to keep things simple. So look forward to
> an update tomorrow:
> + Rule  Flight581       2012 only       -       May     19 14:25
> -2:00   F
> + Zone America/Chicago/Flight581        -7:00   -       PDT     2012
> May 19 14:25
> Ah, but wait, I'm over-reaching. The key is "wall clock time." That
> rules out every clock not attached to a wall. It turns out, none of my
> clocks is attached to a wall, so never mind. It's still a vexing
> problem, though: how do we represent a time zone with no clocks in it?
> Wow. We've got a lot of work to do. Let's to it, then.
> Or, in the alternative, we can just do our best to capture the general
> rules for approximate areas of the planet's surface that have both
> people and clocks, and call it "good enough."

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