diff --git a/docs/changelog/6.x.x.txt b/docs/changelog/6.x.x.txt
index 4af1abe91..df5e7ab77 100644
--- a/docs/changelog/6.x.x.txt
+++ b/docs/changelog/6.x.x.txt
@@ -29,6 +29,7 @@
  - The CS main listing is now 863% faster.
  - Fixed a problem where last reply column wasn't being updated in the thread.
  - fix [ 1488556 ] blank page after setup
+ - fix [ 1489528 ] HTTP header contains invalid time-stamp
 
 
 6.99.0
diff --git a/lib/WebGUI/Session/DateTime.pm b/lib/WebGUI/Session/DateTime.pm
index 90115a2c0..e06c6b118 100644
--- a/lib/WebGUI/Session/DateTime.pm
+++ b/lib/WebGUI/Session/DateTime.pm
@@ -261,6 +261,26 @@ sub DESTROY {
         undef $self;
 }
 
+#-------------------------------------------------------------------
+
+=head2 epochToHttp ( epcoh ) 
+
+Converts and epoch date into an HTTP formatted date.
+
+=head3 epoch
+
+An epoch date. Defaults to now.
+
+=cut
+
+sub epochToHttp {
+	my $self = shift;
+	my $epoch = shift || time();
+	my $timeZone = $self->session->user->profileField("timeZone") || "America/Chicago";
+	my $dt = DateTime->from_epoch( epoch=>$epoch, time_zone=>$timeZone);
+	$dt->set_time_zone("GMT");
+	return $dt->strftime("%a, %d %b %Y %H:%m:%S GMT");
+}
 
 #-------------------------------------------------------------------
 
diff --git a/lib/WebGUI/Session/Http.pm b/lib/WebGUI/Session/Http.pm
index e51ebd0f4..02539b431 100644
--- a/lib/WebGUI/Session/Http.pm
+++ b/lib/WebGUI/Session/Http.pm
@@ -183,7 +183,7 @@ sub sendHeader {
 		$request->status(301);
 	} else {
 		$request->content_type($self->{_http}{mimetype} || "text/html");
-		my $date = $self->session->datetime->epochToHuman(($self->{_http}{lastModified} || time()), "%W, %d %C %y %j:%m:%s %t");
+		my $date = $self->session->datetime->epochToHttp($self->{_http}{lastModified});
 		my $cc = $self->{_http}{cacheControl};
 		$request->headers_out->set('Last-Modified' => $date);
 		if ($cc eq "none" || $self->session->setting->get("preventProxyCache") || ($cc eq "" && $self->session->var->get("userId") ne "1")) {
@@ -195,7 +195,7 @@ sub sendHeader {
     			$request->headers_out->set('Cache-Control' => "max-age=" . $cc.$extras);
   		} elsif ($cc ne "") {
 			$request->headers_out->set("Cache-Control" => "private") unless ($self->session->var->get("userId") eq "1");
-			my $date = $self->session->datetime->epochToHuman(time() + $cc, "%W, %d %C %y %j:%m:%s %t");
+			my $date = $self->session->datetime->epochToHttp(time() + $cc);
     			$request->headers_out->set('Expires' => $date);
   		}
 		if ($self->{_http}{filename}) {