The Google Blog announced that Google will be shortening the expiration date of its cookies from the year 2038 to a two-year life cycle.
If you go to Google.com, Google is to soon set a new cookie to last 2 years from that date. Each time you go back, the cookie will be extended to two years. If you never revisit, it will eventually expire after two years have passed since your last visit.
Google Responds To EU: Cutting Raw Log Retention Time; Reconsidering Cookie Expiration from us covers how Google previous said it was considering cutting the expiration period on its cookies and how the other major search engines have cookies that last from 14 to 30 years.
Google ends by saying:
Together, these steps — logs anonymization and cookie lifetime reduction — are part of our ongoing plan to continue innovating in the area of privacy to protect our users.