March topic(s) for BLU

[jc at trillian.mit.edu (John Chambers)]

Matt Shields wrote:
| Maybe since we're all linux geek we should use a unix timestamp that's UTC

Actually, that's really a "network geek" thing.  Of course, there's a
big  overlap.  But I've often found myself setting my TZ to UTC0 just
to make network stuff simpler.

Funny story: Back in the late 80's, I worked in a lab  that  had  the
fun  of testing a package of networking stuff from 3Com.  It included
what was supposed to be some high-precision  clock  sync  tools.   It
turned  out  that  we  were their first customers that had a LAN that
crossed multiple time zones. We had machines on our "internal" LAN on
both the east and west coast.  We found that at random times, all the
machines on the east coast would jump to Pacific time. We'd fix that,
and  a  while later, all the machines on the west coast would jump to
Eastern time.

We looked at the messages with a line monitor,  and  found  that  the
clock  messages  were  sent in ASCII, which made them easy to decode.
They were local time, with no time zone field. Oops.  I sent in a bug
report suggesting that, to save the sanity of their programmers, they
shouldn't add a time zone; they should make the timestamps  all  UTC.
This  was  apparently a bit of a radical concept to some of them, but
they eventually did it.  It took a few weeks though, so  I  suspected
that  they  had to learn the hard way that local time just won't work
in such tasks.

There's also the observation that back in the early 70's, before unix
escaped  from  Bell  Labs,  the  guys  there had already decreed that
unix's internal clock would always be GMT.   A  century's  experience
with  the  phone system had taught them that that's the only sensible
clock for a system that spans time zones.  It's fun to  watch  people
relearn this lesson over and over, as things move onto the Net.


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 <:#/>  John Chambers
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