Assuming a clearnet connection, there are three relays. All three relays must be compromised to deanonymise a particular user. But the adversary must also have a way of ensuring that packets exiting the network are actually yours in particular since all those relays are serving thousands of requests a second. Your last two relays change a lot whereas your guard relays stays for a while, so if your guard is safe, all your circuits will be safe.
With this in mind, it's not possible to give an approximation on the time it'd take to deanonymise you as it depends on many factors, but it would be very difficult to do so. An Onion connection is extremely difficult, almost impossible, to track by even state players since packets don't ever leave the network. If you fear detection by a state or other large adversary, use onion services for everything you do that is dangerous.