症状

Your instance of Confluence's time is out of sync, either one hour ahead or one hour behind your local time.

原因

You may be using an outdated JDK with an older release of the JRE therein. This is a known issue within Java as Oracle explains in the Timezones, Daylight Savings, and the TZupdater for the Java Runtime Environment (JRE) some versions of  the Java SE JRE do not read the platform's timezone data from the local or host operating system (OS), so OS timezone patches will not update the JRE software's timezone data.

ソリューション

Please upgrade to the latest version of your Java SE JDK release version that is supported in your version of Confluence.