How can I change the date of my appointment with the installation technician?

To reschedule your technician appointment:

1- Log into your account and go to Manage plan.
2- Click on Appointments.
3- Here you will be able to see a complete list of all your past and future appointments.
4- Scroll to the appointment you wish to modify.
5- click on Reschedule.
6- This will open the booking interface. Select a new day and time slot and click Save.

Beware — if you just finished scheduling your appointment, please allow a 3-hour delay for the Reschedule button to appear in your account.

Source: https://fizz.ca/en/faq/how-do-i-manage-appointment-technician-visit-my-service-address

You can just hope that it will change