When Does "The Nice Guys" (2016) Take Place?

"The Nice Guys" is a historical fiction crime film written by Shane Black with Anthony Bagarozzi. The film released May 20th, 2016. 

It takes place in the year: 

1977 AD 

We know this because the film has time and place setting title cards over the opening footage. 

Furthermore, the main characters Holland March and Jackson Healy attend the 1977 Los Angeles Auto Show at about three-quarters through the film. Banners in the background make the year clear.