18 October 1963: Studio recording for "An Unearthly Child" (the version that was broadcast).
18 October 1975: broadcast of fourth episode of Planet of Evil. The Doctor clears the antimatter from the ship and restores Sorenson (who doesn't really deserve it in my view) to his normal self.
18 October 1980: broadcast of fourth episode of Meglos. The Doctor frustrates the evil cactus's plans, Brotadac accidentally destroys Zolfa-Thura, and the Deons and Savants agree to get along better in future.
18 October 1986: broadcast of third episode of Mindwarp (ToaTL #7). Brain transplants and battles; Peri is captured and prepped for her 'orrible fate.
18 October 1989: broadcast of third episode of Ghost Light (the last episode made of Old Who). Light is displeased; the women turn to stone; Control turns into a woman; and I'm sure it made sense to me when I watched it.
18 October 2010: broadcast of first episode of The Vault of Secrets (SJA).