According to https://github.com/log4js-node/log4js-node/blob/master/docs/layouts.md#pattern-format the pattern options are:

%d date, formatted - default is ISO8601, format options are: ISO8601, ISO8601_WITH_TZ_OFFSET, ABSOLUTE, DATE, or any string compatible with the date-format library. e.g. %d{DATE}, %d{yyyy/MM/dd-hh.mm.ss}

These names do not correspond to what is seen in the link specified, see https://www.npmjs.com/package/date-format#formatting-dates-as-strings

I assume this could be because log4js uses an older version? In any sense, it is confusing for users as one cannot check the npm site for the options, as they aren't completely identical.