When Does "Highlander 2: The Quickening" (1991) Take Place?
"Highlander 2: The Quickening" is a science fiction film written by Peter Bellwood with Brian Clemens and William N. Panzer that released January 31st, 1991. So when is "The Quickening" set?
It takes place in the year:
We know this because a very, very early shot of the movie includes the base of a statue with a plaque that reads: "25 YEARS UNDER THE SHIELD 1999 - 2024". So it is during or after 2024 AD.

2024 AD
We know this because a very, very early shot of the movie includes the base of a statue with a plaque that reads: "25 YEARS UNDER THE SHIELD 1999 - 2024". So it is during or after 2024 AD.
Furthermore, the first shot is a white-on-black title card that simply says, "The year is 2024."
More specifically, General Katana observes Connor MacLeod on Earth in the present from planet Zeist in the past on some technology with a time and place stamp reading: "New York City July 16, 2024". So it is probably July of 2024 AD.
The hallmark of the Highlander series is major flashbacks to historical periods but in this installment the only historical flashbacks are to Zeist.
Additionally, there is a flashback to an important recent historical moment from the future's point of view. The subtitle at the first shot of this flashback reads "Shield Control, 1999". Just two shots previously a plague can be seen in front of a model close up that has "December 1999" engraved on it and Doctor Allan Neyman asks MacLeod, "Remember the day?" as the flashback starts. So presumably it is December of 1999 AD at this time.
Also, there is another flashback to the recent past depicting the death of Brenda J. Wyatt. Just before the flashback begins, Connor stands at a memorial plaque reading "BRENDA ELIZABETH MACLEOD ( 1958 ~ 1995 ) BELOVED WIFE OF CONNOR". Later, when Louise Marcus asks about Brenda, MacLeod replies, "She died in New York 29 years ago." So it is 1995 AD at this point.
2,024 - 29 = 1,995.
It is the chronologically last film in the Highlander universe (the fourth chronological film to feature Connor MacLeod) and can be watched at its timeline point after the TV show "Highlander: The Series" (1992) or entirely separately (especially since the Highlander franchise's fans and future writers ignore this story).
There are also multiple alternate cuts of this film under the names the "Renegade Version" and the "Special Edition".

