compile errors on timezone database

Jesper Norgaard Welen jnorgard at Prodigy.Net.MX
Wed Dec 3 06:28:23 UTC 2003

The rules "LastSat 24:00" and "LastSun 0:00" may not always be
equivalent, although I don't know if the specific programming is taking
care of that. But I suspect not.

Consider September 1933, which is within the range of the mentioned
rules. Last Saturday of September is the of September, so
"LastSat 24:00" would change exactly going into Sunday October at
0:00. However, "LastSun 0:00" would be September at 0:00 or
exactly one week before. This really occurs because Sunday October
is not part of September.

I had a similar problem with my definition of a Greenland timezone,
which had the effect that it took place one week from when it should.

I don't know if this actually is calculated like this with the tz
package. I just want to point out the conceptual problem, for your

Jesper Nørgaard Welen

-----Original Message-----
From: Olson, Arthur David (NIH/NCI) [mailto:olsona at] 
Sent: 2. december 2003 15:17
To: Tz (tz at; 'diane_kledzik at'
Subject: RE: compile errors on timezone database

Back in 1998 zic was tweaked to accept 24:00 in "AT" fields; my guess is
that the version of zic being used predates that change. (If the vendor
hasn't stripped things and you're on a POSIX system, you can do a...
	what /path/to/the/executable/zic get a version number; anything under 7.94 lacks the tweak;
anything beyond 7.95 has the tweak.)

Mindful of folks with old compilers, it may be best to change the
northamerica file to avoid use of 24:00, changing the "lastSat 24:00"
references to "lastSun 0:00". (And perhaps using zic should generate
warning messages if a 24:00 shows up and zic's -v option has been


-----Original Message-----
From: Diane Kledzik [mailto:Diane_Kledzik at] 
Sent: Tuesday, December 02, 2003 12:52 PM
To: tz at
Cc: eggert at
Subject: compile errors on timezone database

As an fyi, I receive compile errors when I compile (using "zic") the
time zone database downloaded in the tzdata2003d.tar file from your site.  The error messages read:
"northamerica", line 954: invalid time of day "northamerica", line 955:
invalid time of day "northamerica", line 978: invalid time of day
"northamerica", line 979: invalid time of day

Those lines in the northamerica file are below.  Is it safe to assume I
need to change the 24:00 references to 0:00 instead?  Has anyone else
run into this problem?

Rule    Mont    1927    1937    -       Apr     lastSat 24:00   1:00
Rule    Mont    1927    1937    -       Sep     lastSat 24:00   0

Rule    Toronto 1930    1937    -       Apr     lastSat 24:00   1:00
Rule    Toronto 1930    1937    -       Sep     lastSat 24:00   0

Thanks for your help,
Diane Kledzik

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