From & To rule fields

Philip Warner pjw at rhyme.com.au
Sun Dec 3 04:44:38 UTC 2006


Jesper Norgaard Welen wrote:
> Philip,
>
> my comments below
>   
> ...
> I hope this clarifies the use for you ...
>   
Yes, a great help. You confirmed what I expected...I just did not want
to be heading in the wrong direction.

Which leads to another question: based on the output of zdump, it looks
like rules not strictly included in a zone line are included if the
first rule does not match the time at which the rules are used. Another
example may help (with psuedo-syntax):

Zone Test ... +1:00..........Until 17:00 1-Mar-2000u
                    RuleSet1.....Until 17:00 1-Oct-2000u
                    +2:00..........Until 17:00 1-Feb-2001u
                    RuleSet2.....Until MAX

Rule RuleSet1  1999-Only +3:00 Jan
Rule RuleSet1  2000-Only +4:00 Aug

Rule RuleSet2  2001-Max +5:00 Apr

My understanding of this is that prior to 17:00 1-Mar-2000u, the zone
will be +1:00, then after 1-Mar-2000 it will be +3:00, using the rule
from 1999...then in 1-Aug it will jump to +4:00 and on 1-Oct-2000u it
will swap to +2:00 and will remain there until 1-Apr-2001, since no rule
in RuleSet2 applies until then. But, if we had a new rule:

Rule RuleSet2  1997-Only +6:00 Oct

Then at 1-Feb-2001u it would jump to +7:00.

Again, I'm asking this to confirm my understanding is correct...it
*seems* to be the way it behaves.

Thanks again for your help...







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