Understand the date and age in the HTTP Response Header

Date: The date header field indicates the message sending time. The description format of the time is defined by rfc822. For example, Date: Mon, 31 Dec 2001 04: 25: 57gmt.

Age: When the current server uses its own cached entities to respond to requests, this header indicates that the object is generated fromHow long has it been.

 

 

For example, when you access http://www.yahoo.com/, dateis Fri, 09 Jul 2010 02:02:02 GMT, And it is marked as pagedate.

 

Look at one of the Request http://l.yimg.com/a/ I /mntl/ww/events/p.gif,

Date is wed, 07 Jul 2010 20:53:31 GMT, age is 104913,104913 seconds is converted to 29.1425 hours, date plus age is equal to pagedate, indicating that the current p.gif request is cached by the proxy server and the cache hits.