Google introduced a new META tag that allows you to tell them when a page should be removed from the main Google web search results called unavailable_after tag. This one follows a similar syntax to other META tags. For example, to specify that an HTML page should be removed from the search results after 7pm Eastern Standard Time on 19th August 2007, simply add the following tag to the first section of your page:
<META NAME="GOOGLEBOT" CONTENT="unavailable_after: 19-Aug-2007 19:00:00 EST">
That information will be treated as a removal request, which it will take about a day after the removal date passes for your page to disappear from the search results. Currently they only support unavailable_after for Google web search results.
After the removal, your page will stop showing in Google search results but it is not removed from their system.