When is Montrealhenge?

I was reminded by a Neil DeGrasse Tyson tweet that this is the date of Manhattanhenge, and that we have a henge effect too, as has been discussed in our media previously. The Gazette gave it the date of June 12 in a 2011 piece, and Spacing, back in 2009 – citing an earlier recension of this very blog – also cites June 12, at least from the Plateau grid that’s in line with most downtown streets – a grid that runs east to d’Iberville and north to Jean‑Talon, and is shared by NDG and lower Westmount as well. Other parts of town will not be henging on June 12.