5 CFR § 351.801 - Notice period.
(2) At the same time an agency issues a notice to an employee, it must give a written notice to the exclusive representative(s), as defined in 5 U.S.C. 7103(a)(16), of each affected employee at the time of the notice. When a significant number of employees will be separated, an agency must also satisfy the notice requirements of §§ 351.803 (b) and (c).
(b) When a reduction in force is caused by circumstances not reasonably foreseeable, the Director of OPM, at the request of an agency head or designee, may approve a notice period of less than 60 days. The shortened notice period must cover at least 30 full days before the effective date of release. An agency request to OPM shall specify:
(1) The reduction in force to which the request pertains;
(3) The reasons for the request; and
(4) Any other additional information that OPM may specify.
(d) When an agency retains an employee under § 351.607 or § 351.608, the notice to the employee shall cite the date on which the retention period ends as the effective date of the employee's release from the competitive level.