FreeBSD Support for Leap Seconds

Last modified on 2015-06-29 16:41:41Z by wblock.
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Table of Contents
1. Introduction
2. Default Leap Second Handling on FreeBSD
3. Cautions
4. Testing
5. Conclusion

1. Introduction

A leap second is an ad-hoc one-second correction to synchronize atomic timescales with Earth rotation. This article describes how FreeBSD interacts with leap seconds.

As of this writing, the next leap second will occur at 2015-Jun-30 23:59:60 UTC. This leap second will occur during a business day for North and South America and the Asia/Pacific region.

Leap seconds are announced by IERS on Bulletin C.

Standard leap second behavior is described in RFC 7164. Also see time2posix(3).

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