When to switch to the next 5 year aim?

Hi, I’m trying to create an aim, to orient my life but I am really confused with how long the time horizon should be, and if I should I change the aim a few years in.

Like say I aim to have a bunch of things by the end of 5 years.

But then 2 years in, the 5 year goal, is now 3 years away. Like do I aim at a new 5 year goal?