Google Calendar – SMS Reminder Setup

IFTTT is great for stuff like this. The Date & Time channel is the one you're looking for.

Do you have your phone number associated with your account?

I used the mobile reminder feature in four different European countries, I'd be surprised if it wouldn't work for Canada.

Your screenshot is from the settings for one specific calendar, you need to go to your general calendar settings to associated the phone number:

-> google.com/calendar

-> Options button (right side) -> Preferences

There should be four tabs (General, Calendar, Mobile, Labs)

-> Mobile

enter the number, verify and then go again to the preferences menu for this specific calendar

-> "Calendar" tab

-> TUFIR HAWAT (or any other calendar name)

-> Reminders

the option should now be available