The movie very clearly states that the main action takes place in 1987. Meechum is given an invitation from Madlock to an afternoon party on "Saturday, April 22nd at noon". April 22nd fell on a Wednesday in 1987.
When Cleve holds the gun to Dennis's neck and talks about only a few ounces of pressure needed, the revolver wasn't cocked and significant force would be needed to actually discharge the weapon.
The newspaper clippings in the scrapbook are in fact all the same piece of newsprint, except for each one's opening paragraph.
While the robbery at the beginning of the movie was set in 1972, the robbers are driving a 1975-1978 Ford Econoline van.
After the taxi was blown up, mere blocks from the World Trade Center, both main characters chase after the taxi driver. The next cut is this foot chase, which is clearly in the Times Square/Midtown area of Manhattan, quite a long way away from the WTC down in the Financial District.