New Year's Eve is typically in the depth of end-of-year change freezes for most IT organizations. At the end of 2016, however, two major events will be occurring right at the end of the year: a leap second and the final end of browser support for SHA-1 TLS certificates. Both of these changes have the potential to break software systems and applications. Significant preparation, planning, and testing ahead of time can significantly reduce the risk for both. \r\n The leap second \r\n At the stroke of midnight UTC on New Year's Eve, an extra second will be introduced, effectively causing the last second of the day to last for two seconds. Time will advance from: 2016-12-31 23:59:58 UTC to 23:59:59 to 23:59:60 before reaching 2017-01-01 00:00:00 UTC. This will apply earlier in other time zones. For example, the US East Coast will observe 6:59:60 PM.…