Time of a good Colonial age up, a good FF age up?

Just an example

Like when I finally age up to Colonial, is 5:30 good?

When I finally age up to Fortress, is 8:00 good?

Based on the current fast colonials and fast fortresses strats, what's good times so I won't be late?

Background: I love playing China, I want to develop strategies that'll compete with other civs.