Tomorrow the footers of a great number of websites will automatically change to show a new copyright date. Others will wait for site owners to manually code the change. It’s a change worth making, because it shows visitors that the sites are maintained and up-to-date. As changes go though, it’s a fairly insignificant change, and likely won’t have much influence on the rankings of pages in search results. Many pages on the Web change in minor ways everyday, including updates to visitor counters, subtle changes in formatting, and new advertisements shown on pages.
Many other web pages change in more significant ways on a regular basis, from blog home pages that show new posts, to news media sites that might add new storylines every 15 minutes, to social sites that constantly change as multitudes add updates.
How frequently a search engine crawler might visit a particular page on the Web can depend in part upon how often the page is updated. For example, a news site, updating every hour might have Googlebot or MSNbot sniffing around hourly to devour new content.