30th August 1975: broadcast of the first episode of Terror of the Zygons, launching Season 13. The Doctor, Harry and Sarah, responding to the Brigadier's appeal via space-time telegraph, land in the neighbourhood of Loch Ness
30th August 1980: broadcast of the first episode of The Leisure Hive, launching Season 18. Poor K9 gets short-circuited on the beach at Brighton; the Doctor and Romana head for the famous pleasure planet, Argolis, but the Doctor, investigating a mysterious chamber, apparently gets torn apart. (Perhaps symbolic of new producer John Nathan-Turner's plans for the show.)
30th August 2002: release of fifth episode of webcast Real Time. Cybermen, viruses and the Time Portal; by this stage I'd lost interest in it but I will give it another go some time.