N.Y. Comp. Codes R. & Regs. tit. 12, § 380-3.1 – Employee notice requirements for paid family leave.

(1) When the approximate timing of the qualifying event and need for leave is not foreseeable, an employee shall provide notice to the employer as soon as practicable under the facts and circumstances of the qualifying event. It generally should be practicable for the employee to provide notice of leave that is unforeseeable within the time prescribed by the employer’s usual and customary notice requirements applicable to such leave.
(2) As soon as practicable means as soon as both possible and practical, taking into account all of the facts and circumstances in the individual case. When an employee becomes aware of a qualifying event less than 30 days in advance, it should be practicable for the employee to provide notice of the need for leave either the same day or the next business day. In all cases, however, the determination of when an employee could practicably provide notice must take into account the individual facts and circumstances surrounding the qualifying event.
(c) Intermittent leave.
When an employee takes intermittent family leave the employer may require the employee to provide notice as soon as is practicable before each day of intermittent leave.
(d) An employer may waive the notice requirements contained in subdivision (a) of this section.

(a) Foreseeable leave.

An employee must provide the employer with at least 30 days advance notice before leave is to begin if the qualifying event is foreseeable. Foreseeable qualifying events include an expected birth, placement for adoption or foster care; planned medical treatment for a serious health condition of a family member; the planned medical treatment for a serious injury or illness of a covered service member; or other known military exigency. If 30 days advance notice is not practicable for reasons such as a lack of knowledge of approximately when leave will be required to begin, a change in circumstances, or a medical emergency, notice must be given as soon as practicable. The employee shall advise the employer as soon as practicable if dates of scheduled leave change or are extended, or were initially unknown.

(b)