[TYPO3-english] How to add Last-Modified to header

[Ilya Smirnoff]

Hello!I tring add Last-Modified to header of my site based on TYPO3 6.2.9
and RealURL.
But not success :(
I add to my TS setup this:
config
{
no_cache = 0
sendCacheHeaders=1
enableContentLengthHeader = 1
cache_period = 100
cache_clearAtMidnight = 1
}
But it's doesn't work for me and server answer is:
HTTP/1.1 200 OK
Date: Wed, 29 Apr 2015 10:54:31 GMT
Server: Apache/2.2.22 (Debian)
X-Powered-By: PHP/5.5.20-1~dotdeb.1
Cache-Control: private
Content-Length: 195968
Vary: Accept-Encoding
Connection: close
Content-Type: text/html; charset=utf-8

How I can add something like this:
Last-Modified: Wed, 29 Apr 2015 10:48:39 GMT

Thanks in advance.