Like usual I made my car reservation on travelocity.ca
So my reservation was for friday 7Pm to Sunday 7PM. (2 days)

When I arrived at Union station, the guy at the front desk told me that I will have to pay for 3 Days, because the return location close at 4:30PM on Sunday.

It was not specidied on my reservation neither on the contract.

It's the first company in Toronto, that I have seen, who did that.

I will check with Hertz company if that branch is allowed to do this.

Parking is very, very far from the front desk and not very easy to find.

Other than that car was ok.

At Union Station I will suggest you "Thrifty"/"Dollar rent a car", because they have a shuttle to the parking and you can return the car when you want. (Shuttle only work during business hours.)

FYI I usually rent from Thrifty, Avis, Budget, Entrerprise and Hertz.