Employers can require employees to work overtime. You might try explaining your situation to your boss. Perhaps there are other employees who want the overtime hours. Are you receiving overtime pay? Most employees are entitled to overtime pay when they work more than 40 hours in a work week. If you have not been receiving overtime pay, then you may want to consult in person with an employment lawyer. Good luck.
In Connecticut, under union contracts, employers typically have the right, within some reasonable limit, to require employees to work overtime. Non-union employers can require this as well. The essential element is that adequate notice in advance of the overtime be given to the employees. For occasional and intermittent overtime, notice before noontime is usually considered fair. For more extended overtime, however, a full 24-hour notice is usually expected.
It is considered reasonable to discharge employees who persistently refuse to work overtime; however, to ensure that such discharges are "for cause," employers should give reasonable notice of overtime, insure fair distribution of overtime by way of a roster, use progressive discipline, and be certain they are not interfering with an employee’s rights, e.g., under the Americans with Disabilities Act.
Turning back to your facts, I too would recommend that you speak with your employer. Good luck and best regards, Rob Fortgang