[mythtv-users] INSERT INTO recordedmarkup fails w/duplicate; recording status changes

Stephen Worthington stephen_agent at jsw.gen.nz
Thu Apr 13 17:56:28 UTC 2023


On Thu, 13 Apr 2023 07:26:55 -0700, you wrote:

>UTC and GMT are names given to the time zone which lies on the 0 degree 
>of longitude. Its counterpart on the 180 degree of longitude is the 
>International Date Line.

Not exactly.  GMT was Greenwich Mean Time, which was calculated and
maintained using a mean value of astronomical observations, originally
done at the Greenwich Observatory.  But along came atomic clocks, and
the need for a more accurate time system for scientific purposes, and
later for everyday purposes (such as in the GPS system).  So a new
time system was developed that is based on atomic clocks: Coordinated
Universal Time (UTC).  They are complete time systems, not the names
of time zones, and when used at the same time actually provide
slightly different time, due to how they work.  Once the UTC time
system was adopted, it rapidly became used world-wide, and the
maintenance of GMT was stopped (no more calculations were done and
published) and the GMT time system was abandoned and discontinued. But
the press and everyday usage seems to have kept on using GMT when they
actually mean UTC.  And, it seems that in Britain, the name GMT has
been kept as the name of the local timezone, without daylight saving.
But it is now only the name of a timezone defined by the UTC system as
UTC+0, in the same way that EST is a name for the UTC-5 timezone.

The name UTC is the name of the entire modern time system, but is also
used as an abbreviation for the UTC+0 timezone (with no daylight
saving).

So GMT is acceptable as an alternative name for UTC+0 in Britain.  It
is not acceptable as the name of the time system, or to be used to say
a timezone is GMT-10, unless you really mean the time is an old one
that was calculated back then using the GMT system.

>I guess my preference for GMT is an indicator of my age more than 
>anything else.

Yes, I am also that old.  But using GMT like that is actually
imprecise - you could be meaning the old GMT time system, rather than
the UTC+0 timezone, and they refer to slightly different times.  So it
grates on the sensibilities of those of us who use UTC properly and
prefer to remove such imprecisions and ambiguities.


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