Question

.....against the naval base at Pearl Harbor in Honolulu, Territory of Hawaii, just before 08:00, on Sunday morning, December 7, 1941.
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How do you read "08:00"?

1. eight o'clock.
2. zero eight zero zero
3. O eight O O
4. oh eight oh oh
5. oh eight double o

Answer 1

#1 is the best.

Military people would say, “Oh eight hundred.”

Answer 2

as I see it, #3 and 4 are exactly the same.
By the way, the military people also usually write it 0800, not 08:00.