Oddness in file interpretation - I assume I am missing something...

[Philip Warner]

The current files have the following zone & rules:

Freetown

Zone    Africa/Freetown    -0:53:00 -    LMT    1882
            -0:53:00 -    FMT    1913 Jun # Freetown Mean Time
            -1:00    SL    %s    1957
             0:00    SL    %s


Rule    SL    1935    1942    -    Oct     1    0:00    0    WAT
Rule    SL    1957    1962    -    Jun     1    0:00    1:00    SLST
Rule    SL    1957    1962    -    Sep     1    0:00    0    GMT

And zic produces, among others, the following transition:

Africa/Freetown  Sun Jun 1 00:52:59 1913 UTC = Sat May 31 23:59:59 1913
FMT isdst=0
Africa/Freetown  Sun Jun 1 00:53:00 1913 UTC = Sat May 31 23:53:00 1913
WAT isdst=0

The problem/question I have is: based on the above rules, it is not at
all clear to me that Sat May 31 23:53:00 1913 should be designated
'WAT'; in fact I would have thought there would be a case for it being
'FMT' since none if the 'SL' rules apply in 1913.

This is further complicated by the following rules & zones:

Zone    Africa/Algiers    0:12:12 -    LMT    1891 Mar 15 0:01
            0:09:21    -    PMT    1911 Mar 11    # Paris Mean Time
            0:00    Algeria    WE%sT    1940 Feb 25 2:00
            1:00    Algeria    CE%sT    1946 Oct  7

Rule    Algeria    1916    only    -    Jun    14    23:00s    1:00    S
Rule    Algeria    1916    1919    -    Oct    Sun>=1    23:00s    0    -

which for the transition in 1911 produces 'WET'; apparently *not* using
the 'S' from the first rule.

And this set:

Zone    Africa/Accra    -0:00:52 -    LMT    1918
             0:00    Ghana    %s

Rule    Ghana    1936    1942    -    Sep     1    0:00    0:20    GHST
Rule    Ghana    1936    1942    -    Dec    31    0:00    0    GMT

which produces 'GMT' for the transition in 1918.

Can someone confirm that zic is doing the right thing (which I kind of
assume it is by definition), and perhaps give me a rule to follow when
performing the %s substitutions?

Any help would be greatly appreciated.