Google News includes articles that have been crawled within the last 30 days. Our crawler will only index new content that is less than 48 hours old. Similarly, if you make changes to an article 48 hours after it appears in Google News, it's very unlikely our system will discover and register this change.
We encourage you to format the publication dates of your articles in a way that is easy for our crawler to interpret. Please review our tips for formatting publication date for more information. Additionally, submitting a Google News Sitemap helps our system discover your content faster. If you do submit a sitemap, please make sure it only includes your newest articles.
For those looking for older news content, you may want to try Google News Archive Search 
.