41 CFR § 301-11.23
Are there any other circumstances when my agency may reimburse me to return home or to my official station for non-workdays during a TDY assignment?
June 9, 2020
Your agency may authorize per diem or actual expense and round-trip transportation expenses for periodic return travel on non-workdays to your home or official station under the following circumstances:
(a) The agency requires you to return to your official station to perform official business; or
(b) The agency will realize a substantial cost savings by returning you home; or
(c) Periodic return travel home is justified incident to an extended TDY assignment.