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.
Employee Notice Requirements. The main employee notice requirement under the FMLA is that employees must inform employers of their need to take FMLA leave. When the employee's need for leave is foreseeable, the employee must generally give at least 30 days' notice.