Time and practicality are two separate things. We have time to do something about it, but it's not actually all that certain that anything we can do will have any real effect, even hitting it with nukes isn't a certain bet, we don't have the technology to do that using an Earth-Launch until it is dangerously close, and orbital launchers are still more part of the whole 'Star-Wars' thing than a viable concept.
I suspect we could take action against it, but that action will still be hit or miss, we'd do better, to be honest, looking at something like a coilgun or particle accelerator of some description, you can launch from much further away, giving you a few goes at hitting it.
