Vzic indicates missing tz rules

[Paul Eggert]

Andy McDonald <andy_tz at stemhaus.com> writes:

> Rule	NT_YK	1918	only	-	Apr	14	2:00	1:00	D
> Rule	NT_YK	1918	only	-	Oct	27	2:00	0	S
> ...
>
> Zone America/Inuvik	-8:54:52 -	LMT	1884
> 			-8:00	NT_YK	P%sT	1979 Apr lastSun 2:00

In situations like these, zic assumes that standard time is in effect
before the first Rule line takes affect, so it uses the first
standard-time rule letter it sees.  At least, that's my understanding
-- I haven't looked at the code recently.