Employee Notice Requirements. The FMLA requires employees to give notice of their need to take FMLA leave. Here are some of the changes the new regulations make to these requirements: The new regulations require employees to give notice 30 days in advance if their need for FMLA leave is foreseeable, just as the old regulations did. Now, however, an employee who does not give 30 days' notice must explain why such notice was not practicable, if the employer requests.