[tz] historic Oslo times

[Meno Hochschild]

Recently I noticed following strange detail of Europe/Oslo during the 
years 1940-1942:

The site http://www.timeanddate.com/time/zone/norway/oslo reports for 
these years that Oslo kept summer time between 1940-08-10 23:00 and 
1942-11-02 03:00. But I cannot find a way in tz-data how to construct 
it. Maybe I have overlooked something.

Rule Norway 1916 only - May 22 1:00 1:00 S
Rule Norway 1916 only - Sep 30 0:00 0 -
Rule Norway 1945 only - Apr 2 2:00s 1:00 S
Rule Norway 1945 only - Oct 1 2:00s 0 -
Rule Norway 1959 1964 - Mar Sun>=15 2:00s 1:00 S
Rule Norway 1959 1965 - Sep Sun>=15 2:00s 0 -
Rule Norway 1965 only - Apr 25 2:00s 1:00 S

# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone    Europe/Oslo    0:43:00    -    LMT    1895 Jan 1
1:00 Norway CE%sT 1940 Aug 10 23:00
1:00 C-Eur CE%sT 1945 Apr 2 2:00
1:00 Norway CE%sT 1980
1:00 EU CE%sT

The Norway-rules do not catch the year 1940, so cannot indicate any 
summer time until 1940-08-10. Then the C-Eur-rule takes effect but see here:

Rule C-Eur 1940 only - Apr 1 2:00s 1:00 S
Rule C-Eur 1942 only - Nov 2 2:00s 0 -

The rule for 1940 cannot be applied because 1st of Apr is clearly before 
the UNTIL-date of zone line in question when changing from Norway-rule 
to C-Eur-rule. I assume we are missing an extra Norway-rule for 1940 
only changing to summer time on 1940-08-10 and have then to shift the 
UNTIL-date in second ZONE line a little bit (for example to 1941).

Thanks in advance for any help

Meno Hochschild