[what's up]

I would think the Greek enlightenment would begin in Ionia with the pre-socratics.

Weren't they in the 6th century?

[Cicero]

Sure, the pre-Socratics were important, and Homer was no slouch, either.

But it's commonplace to refer to the Age of Pericles or the Golden Age of Athens in the Fifth century.

You can do similar things with the Renaissance, moving it earlier, since there aren't always distinct lines. For instance, many historians speak of a Renaissance of the 12th century. But normally when you use the word it means somewhat later, maybe the fifteenth century in Italy.