here is a good explanation by Erin (lol, madhur_ahuja beat me to it):
https://www.urch.com/forums/faqs/700-gma ... l#post1715
basically, from what I can understand, 2 rules apply here: 1: using participal phrases can be parallel regardless whether you use past or present participals; 2: past participal indicates a passive relationship between the noun/subject and the phrase/action, present participal indicates an active relationship.
so back to the question, local times, "determined by...then sun" <--- passive relation
and local times "differing from city to city" <--- active relation. The hard part is reading the word "differ" as a participal rather than as a real verb.
an example helps:
The piano, differing from other instruments, is one of the most expensive.
The piano, differed from other instruments, is one of the most expensive.
Which one "sounds" better? the active voice.
The local times, differing from city to city, was abolished.
The local times, differed from city to city, was abolished.
Note the tense of the main clause (was) doesn't matter; it's the active-passive voice that matters.