Here's the math.
Block time 15:45 each trip. = 78:45
Duty day, assuming 75 minutes before and 15 minutes after, 19:15 - 91:15

There's probably a minimum monthly guarantee and a higher number where after that overtime is paid.

The crew will refer to this as a 3 day pairing. Even though the car is in the parking lot less than 48 hours.

The example must enjoy this kind of pairing(punishment) for personal reasons.

By comparison, YUL-YVR return would be about 10 hours block time return.
With a YVR overnight, that would be 16 days of work/month.