I'm using ipinfo.io to look up geolocation data of a list of IP addresses that have accessed my database over the course of nearly two years. I'm curious about the time-dependance on the accuracy of the geolocation data.
For example, suppose someone accessed my server from an IP address in January 2017. Is it possible that when I look up that address now (December 2018) that I get a different result than if I had looked it up in January of 2017?
The answer is yes. IP address allocation required yearly renewal, else it will be reallocated to other owners. Some ISP will also reassign their IP address to different location frequently within their network.
In this case, you should not use the 2018 database for 2017 IP addresses.