I do the research for each day's anniversaries on the Tardis Index File (Doctor Who wiki), but rather than just use the individual pages for each date (such as the one for today) I use the list of pages linking to that date (again, such as the one for today) and follow through each link to see if it is worth noting. Actors get listed if they have played a significant speaking role in more than one story. Writers, directors, and senior production team get listed if they have worked on any story at all and their birthdate is known to the Tardis Index File. Broadcast anniversaries always get included; other significant performance and production anniversaries almost always. I may sometimes skip dates supposedly specified in canon if it's a spinoff story I haven't heard of, or worse have actually read / watched / heard but can't remember, but will try and err on the side of inclusion as well. I usually prepare the posts a couple of days in advance - they are synchronised across my various computers and my phone using Evernote, which I heartily recommend.
I started by posting to both my own LJ account and to doctorwho, and will probably continue this but will lj-cut the posts to my own account even more than I currently do. The doctorwho posts go through to my Twitter account (@nwbrux) but not to my Facebook feed which is full enough anyway.
Now that I've put the work in for half the year, I am thinking abou how to preserve the project, or even add to it, in some way other than in LJ archives. If I had the time and energy, I'd put some effort into updating the Tardis Index File daily pages, but there may be scope for some other way of presenting the info as well. I'd be very keen to hear thoughts from other people.
Anyway, on with today: three births, and seven broadcast anniversaries (including a record-breaking three on the same day, 1 January 2007), but no dates specified in canon other than follow-ons from yesterday's rather large crop.
i) births and deaths
1 January 1935: birth of Dave Martin, co-author with Bob Baker of The Claws of Axos (1971), The Mutants (1972), The Three Doctors (1973), The Sontaran Experiment (1975), The Hand of Fear (1976), The Invisible Enemy (1977), Underworld (1978) and The Armageddon Factor (1979) as well as four spinoff novels.
1 January 1969: birth of Sophie Okonedo, who played Alison in Scream of the Shalka (2003) and Liz 10 in The Beast Below (2011).
1 January 1979: birth of Freema Agyeman, who played Martha in New Who's third season (2007) and returned for a few episodes of the fourth season and the second season of Torchwood (both 2008) and a cameo in The End of Time II (2010).
ii) broadcast anniversaries
1 January 1966: broadcast of "Volcano", eighth episode of the story we now call The Daleks' Master Plan. The Daleks realise that the Taranium core is a fake; the Doctor, Steven and Sara encounter the Meddling Monk on the planet Tigus, also passing through Lord's cricket ground and Trafalgar Square for New Year's Eve.
1 January 1972: broadcast of first episode of Day of the Daleks, starting Season 9. Diplomat Sir Reginald Styles is under attack by mysterious guerrillas from a Dalek-dominated future.
1 January 1977: broadcast of first episode of The Face of Evil. First appearance of Louise Jameson as Leela. Leela is exiled from the tribe of the Sevateem for blasphemy; the Doctor finds that the Evil One has a familiar face.
1 January 2007: broadcast of Invasion of the Bane, the first episode of the new Sarah Jane Adventures. Sarah, her young neighbour Maria, and Maria's annoying friend Kelsey (who is never seen again) team up to discover that the alien Bane are behind the new Bubble Shock! soft drink; Sarah adopts the human boy at the centre of their plan.
Also 1 January 2007: broadcast of Captain Jack Harkness (Torchwood), the one where the team get timeshifted back to 1941 and Jack falls in love with his namesake.
Also also 1 January 2007: broadcast of End of Days (Torchwood), the one where the big demon thing kills both Rhys and Jack but they come alive again.
1 January 2010: broadcast of The End of Time II, the last episode for the Tenth Doctor. The Time Lords return; the Master is persuaded to blast them back into the Time War; and the Doctor rescues Wilf, at the cost of his own life. And the new Doctor yells, "Geronimo!!!!"