Issuing the request below, for example, will make Artifactory to return date headers (date and/or last-modified) in EDT timezone:
$ curl -H "If-Modified-Since: Thu, 12 Mar 2020 14:40:22 EDT" http://localhost:8081/artifactory/debian-remote/dists/bionic/InRelease
Sample response:
< HTTP/1.1 304 Not Modified
< Server: Artifactory/6.18.1
< X-Artifactory-Id: 524308758461d139:265b2f25:17117c618bd:-8000
< Last-Modified: Fri, 27 Apr 2018 01:38:40 CEST
< ETag: e0f89a6606e9968eb67caffb23366793ea9d2800
< X-Checksum-Sha1: e0f89a6606e9968eb67caffb23366793ea9d2800
< X-Checksum-Sha256: 690bd875ab5799394af7406f32f2e698c48e772ac367d520f74ec1095662da4d
< X-Checksum-Md5: a510315c6a7499fe9c1f34fd2edf2812
< Accept-Ranges: bytes
< X-Artifactory-Filename: InRelease
< Content-Disposition: attachment; filename="InRelease"; filename*=UTF-8''InRelease
< Cache-Control: no-store
< Date: Thu, 26 Mar 2020 13:18:59 EDT
HTTP (RFC2616) specifies: All HTTP date/time stamps MUST be represented in Greenwich Mean Time (GMT), without exception.
https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.3.1
The issue appears to be due to Tomcat upgrade to version 8.5.51, which has the following issue: https://bz.apache.org/bugzilla/show_bug.cgi?id=64226