id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
206	$start_time http variable	www.boldpx.com	somebody	"There's a series of patches for nginx that have been circulating for some time that add a $start_time HTTP variable. The $start_time variable tends to be used for application metrics, such as New Relic.

https://newrelic.com/docs/features/tracking-front-end-time#implementation

This seems like a feature that would be useful to have built-in. This is the most up-to-date patch I know of.
https://gist.github.com/2890138/

"	enhancement	closed	minor		nginx-core		wontfix				1.2.3