Medical experts usually say the average person can live for 4 to 6 weeks without food. The amount of time someone can go without water is much shorter, roughly a week (or less).
Your employer can force you to take leave at a particular time as long as they give you at least two weeks' notice. However, it is common for employer and employee to come to an agreement about the timing of annual leave. If you put in a request for leave, your employer has to have a good reason to refuse it.
Under the federal Workers Adjustment and Retraining Notification Act, you must give your employees at least 60 days of advance written notice before terminating them if you are laying off 50 or more employees at one site or one-third of your full-time employees. Otherwise, you do not have to provide any notice.