A JsonTemplateLayout user has reported <https://issues.apache.org/jira/browse/LOG4J2-3073?focusedCommentId=17323825&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17323825> that the following JSON template
{ "@timestamp_nano1": { "$resolver": "timestamp", "pattern": { "format": "yyyy-MM-dd'T'HH:mm:ss.SSSSSSSSS'Z'", "timeZone": "UTC" } } resolves to { "@timestamp_nano1": "2021-04-16T13:09:16.000000008Z" } Internally, processing is performed by TimestampResolver in JTL module, which utilizes FastDateFormat. Does anybody have an idea about the missing precision?