I'm going to say it's mid eighties. There is no Terminal 3 at the airport, Finch W. doesn't cross the Humber River at Islington yet and the 410 is built north of Derry Road (early eighties).
Well, I can tell you I'm currently looking at my 1992 Canadian Oxford School Atlas which has a nice Landsat image of Toronto on page 9 which looks rather different from the one above (albeit mainly in the colouring). Unfortunately it doesn't specify which Landsat its from, other than the fact it would have to be #5 or earlier as #6 went up in 1993.
Well, I can tell you I'm currently looking at my 1992 Canadian Oxford School Atlas which has a nice Landsat image of Toronto on page 9 which looks rather different from the one above (albeit mainly in the colouring). Unfortunately it doesn't specify which Landsat its from, other than the fact it would have to be #5 or earlier as #6 went up in 1993.