"David Braverman" <david@inner-drive.com> writes:

... Rule US 1918 1919 - Oct lastSun 2:00 0 S Rule US 1942 only - Feb 9 2:00 1:00 W # War Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace Rule US 1945 only - Sep 30 2:00 0 S ...

I can't tell what rule to follow from 1942-01-01 to 1942-02-19, then from 1943-01-01 to 1945-08-14.

I'd say it's the last US rule in effect, which is 1919 Oct lastSun at 2:00, i.e., standard time. You can debug your understanding by using the command "zdump -v America/Chicago".