where the date in response header be set?
I had a same questions like you, and found it.
See org.apache.coyote.http11.Http11Processor.java 1246:1(org.apache.tomat.embed:tomcat-embed-core:8.5.15)
// Add date header unless application has already set one (e.g. in a// Caching Filter)if (headers.getValue("Date") == null) { headers.addValue("Date").setString(FastHttpDateFormat.getCurrentDate());}