Implementation of UTC-compliant Leap Seconds in Microsoft Windows

Abstract

Regulations governing fairness in the financial markets mandate accuracy and traceability at all times, including during leap seconds. Leap seconds are difficult for computer systems to implement in accordance with the UTC definition for a variety of reasons. This paper discusses the implementation of UTC-compliant leap seconds in Microsoft Windows 10 October 2018 Update and Windows Server 2019, the adaptations we have put in place to address potential application compatibility issues, and demonstrates high accuracy time keeping when leap seconds roll over.