2366

In 2366, in a parallel universe, a time sensitive name Guinan began receiving memories of things she shouldn't have remembered, mostly concerning the borg/cybermen. Two years later, she met The Doctor and confirmed with him these suspicions. (COMIC: Assimilation²)

The Macra Terror was arbitrarily dated to 2366 (a time when Earth's colonies are remote and the levels of technology aren't very high) according to A History of the Universe and AHistory.