Last Modified, Dates and Timezones in Sitemapper
Sitemap generator will during its crawl extract last modified values from meta tags and HTTP headers.
Our software product
A1 Sitemap Generator extracts these values in one of the following ways:
- Checks if the webserver responds with last-modified HTTP response header:
HTML pages: The webserver will usually generate this header for you.
PHP example: Extract last-modified from file:
<?php header("Last-Modified: " . gmdate("D, d M Y H:i:s", filemtime($SCRIPT_FILENAME)) . " GMT"); ?>.
ASP example: Set hard coded last-modified:
<% Response.AddHeader "Last-modified","Mon, 01 Jan 2000 11:22:33 GMT" %>.
ASP.Net functions you can check documentation on:
Response.Cache.SetLastModified(DateTime date);
Response.Cache.SetLastModifiedFromFileDependencies();
Response.AddFileDependancy(string filename);
- If no relevant HTTP response header, the page is checked for last-modified HTML meta tag.
You can always view the
last-modified values retrieved in
page data.
Note:
The server timezone will often be
placed and configured to be different
from your timezone. The date and time the server returns in
last-modified
depends on the server computer clock. This again depends on how the server timezone and clock has been configured.