The times should definitely be moved earlier in the day for EST. Having one in the middle of the night and then the next 3 more than 12 hours later makes no sense at all.
They should add in 1 more harbor and then it would make much more sense to have them at 9am, 12pm, 3pm, 6pm, 9pm (the new one).
Those times for the 4 original harbors don't, necessarily, exclude anyone (as far as I can tell).
I would think that North and South America along with European players can play the above times reasonably well without completely excluding people with times at 3am or something.