Per LOGBACK-262 [1], logback does not conform to ISO8601 when printing %d{ISO8601}. We're in the process of fixing this [2], but we'd like to maintain backward compatibility for log parsers that might rely on the incorrect format. We have a couple options.
OPTION 1. Add a new option for %d that enables the legacy incorrect format. Deprecate it, and remove it after several releases. Examples:
%d{ISO8601_OLD}
%d{NOT8601}
%d{OLD8601}
%d{ISO8601,,old}
other?
OPTION 2. Force users to specify a custom date format that matches the legacy incorrect format:
%d{"yyyy-MM-dd HH:mm:ss,SSS"}
Please provide feedback on these options (or a new one) by June 23.