(1) If the necessity for leave for the birth or placement of a child with the employee is foreseeable based on an expected birth or placement, the employee shall provide the employer with not less than thirty days' notice, before the date the leave is to begin, of the employee's intention to take leave for the birth or placement of a child, except that if the date of the birth or placement requires leave to begin in less than thirty days, the employee shall provide such notice as is practicable.

(2) If the necessity for leave for a family member's serious health condition or the employee's serious health condition is foreseeable based on planned medical treatment, the employee:

(a) Must make a reasonable effort to schedule the treatment so as not to disrupt unduly the operations of the employer, subject to the approval of the health care provider of the employee or the health care provider of the family member, as appropriate; and

(b) Must provide the employer with not less than thirty days' notice, before the date the leave is to begin, of the employee's intention to take leave for a family member's serious health condition or the employee's serious health condition, except that if the date of the treatment requires leave to begin in less than thirty days, the employee must provide such notice as is practicable.

(3) The employer may waive any or all of the employee notice requirements in this section and in RCW 50A.15.040(1)(f).