The Ministry of Time by Kaliane Bradley Hardback

In the near future, a disaffected civil servant is offered a lucrative job in a mysterious new government ministry gathering 'expats' from across history to test the limits of time-travel.

Her role is to work as a 'bridge': living with, assisting and monitoring the expat known as '1847' - Commander Graham Gore. As far as history is concerned, Commander Gore died on Sir John Franklin's doomed expedition to the Arctic, so he's a little disoriented to find himself alive and surrounded by outlandish concepts such as 'washing machine', 'Spotify' and 'the collapse of the British Empire'. With an appetite for discovery and a seven-a-day cigarette habit, he soon adjusts; and during a long, sultry summer he and his bridge move from awkwardness to genuine friendship, to something more.