@Fanboys apologise for Google
Alta Vista does NOT do what you say it does. The search option (see below for quote from documentation) looks for pages created OR MODIFIED withing the given date range. It also adds a warning about the accuracy of dates.
Perhaps it is you who should RTFM?
So, the only place to get data is XML tags in the feed or the raw data of the article. As detailed above, neither of these will work.
Oh, and I post as AC to avoid trouble at work, and far from finding "simple exercises so difficult", I am too experienced to assume that the underlying problem is simple just because it sounds simple.
From the Alta Vista documentation:
This feature enables you to find Web pages that were created or modified in a time range that you can specify. Please keep in mind that some Web servers do not provide accurate modification dates for the pages they host.
- Select a time range from the menu or
- Type a date range into the from/to boxes.