13 June 1964: broadcast of “The Day of Darkness”, fourth episode of the story we now call The Aztecs. Cameca helps the Tardis crew escape, and Aztec history continues as it had always done.
13 June 1970: broadcast of sixth episode of Inferno. The Doctor and friends fight through to the Tardis console in the parallel Earth, and the Doctor escapes though the others are doomed.
It was the last three that did me, the one that starts next to Mali, the one that looks a lot like Batman and is hanging over Siberia and the one that started over Tasmania.