It's 3 years from the device's release. You get the next two major OS updates (which occur at ~1 and ~2 years after release), and then another full year of secu

It's 3 years from the device's release. You get the next two major OS updates (which occur at ~1 and ~2 years after release), and then another full year of security updates, up to but not including the third major OS version.