[Scarlett.]

When the programme began, it was set in 1964. The setting then moved on, approximately in "real time", until it reached early 1969, where – apart from the Christmas episodes – it has now remained for some years. However, the show's chronology has been seen to be quite flexible: the inhabitants of Ashfordly and Aidensfield have certainly celebrated more than four Christmases between 1965 and 1969.

The 1998 episode "Heartbeat: Changing Places", which follows Sgt. Rowan as a Mountie, opens with the caption "1968". This is sometimes said to be the only explicit time reference in the series, though one 2004 episode was specifically set on 6 February 1969, the date being deliberately displayed clearly in an extreme close-up of "today's newspaper". Whenever a car or motorcycle's tax disc is shown on screen, it is always valid until 31 December 1969. However, the show often depicts steam trains still in service on British Railways, which is incorrect for 1969 since steam-hauled passenger services finished in August 1968.

The Torrey Canyon oil spill provided an off-screen plot point in a series ostensibly set in 1969, despite having actually occurred two years earlier. An episode broadcast in August 2007, "One Small Step", depicted the people of Aidensfield gathering in the pub to watch the Apollo 11 moon landing, which precisely "dates" the story to 20 July 1969, though it was actually aired just three weeks after an episode that was clearly set in winter. This has led some to speculate that the series intends to move into the 1970s. Perhaps anachronistically, the episode featured an early example of Apollo Moon Landing hoax accusations – Peggy Armstrong casts doubt on the authenticity of the mission and takes fake photos of David Stockwell in a space suit to prove her point. The locals are unimpressed by her efforts. The series 16 finale used the Northern Ireland "Troubles", generally acknowledged as starting in 1969, as a plotline.

Additionally, in the second episode of series 17 entitled 'Night Mail', some may have also noticed the tax disc displayed on the windscreen of the police car PC Joe Mason and DS Rachael Dawson were sitting in, was due to expire at the end of December 1969.

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