Proxy refresh query

Hi, usually how long after getting fresh proxies from your provider do the old ones stay active for?
Is it prudent once u get the new proxies to input them into the accounts right away or do you get a few days grace before they are no longer active?

Cheers.

from what i know fresh proxies means you get new proxies instead of the old ones, this means the old ones stop working as soon as they ware changed with the new ones, you don’t have access to both of them for a certain period of time.