Toshiko Sato was working in a London hospital when a pig-like "alien" was brought in during March of 2006 ('Doctor Who' - "Aliens Of London"). According to the 'Torchwood' episode "To The Last Man", Tosh has been with the Cardiff branch of the Torchwood Institute for four years.
That makes the current crop of episodes as taking place in 2010.
In "To The Last Man", Captain Jack made a point of adjusting his desk "calendar" so that it read "Friday 20".
There is only one option for a Friday the 20th in 2010 - August.