Lots of valid dates from October all the way through the beginning of June.
Can book one way too, no need for RT. $81.73 for SFO-YYZ and $115.36 for YYZ-SFO.
Flights connect in either: ATL, DTW, JFK, MSP or SLC.
This can work great also for hidden city SFO to JFK at only $81.73,
Flights can also be booked on most dates for 9,500 skymiles.