How do we determine a year on Earth? There are a few factors to consider when determining a "calendar" year, including the means of measurement. After this video, you wont look at our annual revolution the same way.
Warning: Unknown: Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively in Unknown on line 0