Can the new owner change my schedule without asking me first?

To a real degree, yes — scheduling is an area where employers generally have meaningful discretion, and a new owner reorganizing how a business runs is allowed to adjust shifts, hours, and rotations without needing your individual sign-off for every change, as long as the changes stay within the basic scope of the job you were already doing.

Where this becomes more than ordinary managerial discretion is if the schedule change is severe enough to amount to a fundamental change to your employment — cutting your hours dramatically, moving you to entirely different shifts that were never part of your original job, or effectively making the position unworkable for you. That kind of change can carry real consequences for the employer even without a formal termination. Ontario's Employment Standards Act, 2000 also has its own separate rules protecting employees from certain kinds of reduced hours being treated as a disguised layoff.

If your schedule changes in a way that feels manageable but unwelcome, that's likely within the new owner's discretion; if it changes so much that the job barely resembles what you signed up for, document exactly what changed and when, and get advice about your options.