This article provides information on Plesk product and leap seconds.
Leap second is a one-second adjustment of Coordinated Universal Time (UTC) in order to keep a system's time of day close to the mean solar time. However, the Earth's rotation speed varies in response to climatic and geological events, and due to this, UTC leap seconds are irregularly spaced and unpredictable. This article seeks to provide information regarding the leap seconds themselves, along with addressing how Plesk handles the insertion of one.
Upcoming Leap Second Events
Please refer to the latest IERS Bulletin C on the http://www.iers.org website.
Note: No issues have been reported regarding leap second and its influence on Plesk during the last leap second events on 2005, 2008, 2012 and 2015.
Based on the current experience, leap second would not affect Plesk.
Possible side-effects are:
Statistical data which is calculated during the minute with the leap second will not contain information about the events which occurred during the leap second (for Windows systems);
Statistical data which is calculated during the minute with the leap second will contain double information about the events which occurred during the leap second (for Linux systems);
Events that take place upon determined period of time, might occur on the next period of time. For example: subscription might expire one day later, notification might be sent on the next day, grey-listing expiration might occur with a 5 minute delay.
All Plesk services are connected with the system time - that is why they will grab the new time automatically. Therefore it is recommended to explore known issues regarding the leap second for a particular operating system.