Olson database name ambiguity

Dave Rolsky autarch at urth.org
Mon Mar 7 16:02:22 UTC 2005

On Mon, 7 Mar 2005, Tom Yandell wrote:

> Apologies for cross posting this. I think that this is a problem in the
> data in the Olson database, but as it is a binary format it is difficult
> to verify this. I have come across this problem using the DateTime perl
> module (version 0.28) whose data is generated from the Olson database.

The text versions of the Olson database are available here: 

> The problem that I am experiencing is that the short name for timezones
> for 'Europe/London' up until 1996 were either 'GMT' or 'BST' (depending
> if daylight saving changes were in effect). From 1996 the name for the
> timezone is the rather less precise 'GMT/BST' regardless of whether
> daylight saving changes are in effect or not. I have attached a script
> that demonstrates this, and its output.

Ah, I see.  I think my parser interprets the data in the Olson db 
incorrectly.  The db does just list "GMT/BST", but apparently that means 
they alternate, not that there's just one short name for that zone at all 

Parsing the Olson DB is, ahem, not exactly fun ;)

I'll fix this in the next release.


VegGuide.Org                        www.BookIRead.com
Your guide to all that's veg.       My book blog

More information about the tz mailing list