Final answer:
A sailor who started active duty on January 23, 1999, and became a Chief Petty Officer could typically serve up to 24 years, potentially serving until January 23, 2023, barring any tenure policy changes or individual exceptions.
Step-by-step explanation:
A sailor who began active duty on January 23, 1999, and was later advanced to the rank of Chief Petty Officer (CPO) would be subject to the high-year tenure policies of the U.S. Navy. This policy determines the maximum length of service that personnel in various ranks can serve. However, without specific details about changes to the U.S. Navy's high-year tenure policy since 1999, it's not possible to provide an accurate maximum date of service for the sailor in question.
Typically, CPOs could serve up to 24 years of active service, after which they would be expected to retire unless they had received special waivers or extensions. With that in mind, a CPO could potentially serve until January 23, 2023, if they entered service on January 23, 1999. This assumes no changes to policy or individual circumstances that would affect the tenure limit.