There is information on your Travel Blog that is time sensitive. For example, the number of countries you have visited will continually change. There is also prices of Hotel rooms, and other information.
Place the date under the post or near i.e.
--- Updated June 2010 ---
List of Items that need Date
1. Price of Hotel Rooms
2. FAQS or Frequently Asked Question
3. List of countries you have visited.
It is possible to put a java script information or data plug on the site, and just change in one location.
Please date you Travel Blog post and remember, this post could be relevant for years, but money, dates, facts will not.