I would not take the "index*.html" as an authoritative source. I'd typically use for these sort of questions
wget -S --spider ... which shows the HTTP header information without downloading the file (note: this needs the fully fledged version of it from the 'wget.tcz' extension):
tc@box:~$ wget -S --spider http://distro.ibiblio.org/tinycorelinux/3.x/tcz/Xlibs.tcz
Spider mode enabled. Check if remote file exists.
--2011-07-31 16:32:48-- http://distro.ibiblio.org/tinycorelinux/3.x/tcz/Xlibs.tcz
Resolving distro.ibiblio.org (distro.ibiblio.org)... 152.19.134.43
Connecting to distro.ibiblio.org (distro.ibiblio.org)|152.19.134.43|:80... connected.
HTTP request sent, awaiting response...
HTTP/1.0 200 OK
Content-Type: application/octet-stream
Accept-Ranges: bytes
ETag: "691799274"
Last-Modified: Wed, 15 Jun 2011 19:52:54 GMT
Content-Length: 2854912
Connection: keep-alive
Date: Mon, 01 Aug 2011 05:28:23 GMT
Server: lighttpd/1.4.26
Length: 2854912 (2.7M) [application/octet-stream]
Remote file exists.
Please turn your attention to the Last-Modified field which clearly shows that Robert's information was correct (i.e. '15 Jun 2011 19:52:54 GMT').