London (GMT) notation self-conflicts

BRUIN Paul pbruin at
Thu Nov 1 16:30:06 UTC 2007


Thank you for persuing this.  The upshot is that this relates to internal nomencature within my company and does not occur in your database.



-----Original Message-----
From: Olson, Arthur David (NIH/NCI) [E] [mailto:olsona at] 
Sent: Thursday, November 01, 2007 7:14 AM
To: tz at
Cc: BRUIN Paul
Subject: FW: London (GMT) notation self-conflicts

I'm forwarding this message from Paul Bruin, who is not on the time zone mailing list.

Those of you who are on the time zone mailing list should direct replies appropriately.


From: BRUIN Paul [mailto:pbruin at]
Sent: Wednesday, October 31, 2007 11:58
To: tz at
Subject: London (GMT) notation self-conflicts

My company's application servers use the Olson database as a time zone reference. The following listings appear, which I believe are so-named in the Olson database: 
London (Greenwich Mean Time)
Belfast (Greenwich Mean Time)
Dublin (Greenwich Mean Time)

These notations are correct only in winter, when all three cities are on GMT.
But in Summer, these cities are GMT+1.
This means that in summer, there is a conflict within the notation. 

Note that this conflict does not arise for cities outside the United Kingdom.
Taking Paris (Central European Time) as an example, Paris time and Central European Time are always the same, irrespective of the extra hour of Daylight Savings offset from GMT in summer.

To fix this, "Greenwich Mean Time" should be removed from the notation for London, Belfast and Dublin.
It  might be replaced by "United Kingdom Time," "British Isles Time" or "British Time." 
Does this conflicting notation indeed exist in the Olson database and, if so, can it be fixed? 
Thanks for your help,
Paul Bruin
pbruin at
415-924-8702 (office)
415-706-0442 (cell)
17 Skylark Drive, #39
Larkspur, CA 94939

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