过期值如何用于Cookie和缓存？ [英] How do expire values work for cookies and caching?

问题描述

过期值总是困惑我，因为客户端的时间设置可以完全不同于服务器。我想知道在幕后发生了什么。

说我的服务器的时区是GMT +1，客户端的时区是GMT + 2.如果我现在创建cookie with as expires value： current_timestamp + 31 * 86400 （过期在31天），浏览器如何知道正确的时间？到期时间是否转换为GMT值，然后由浏览器转换为客户端的正确时区？

解决方案

Cookie过期标题的格式包含时区，因此Cookie何时过期不会出现歧义

http://www.cookiecentral.com/faq/#3.2

  Set-Cookie：foo = bar; path = /; expires Mon，09-Dec-2002 13:46:00 GMT 
  

Expire values have always confused me, since the time settings of the client can be completely different from the server's. I'd like to know how what happens behind the scenes.

Say my server's timezone is GMT +1 and the client's timezone is GMT + 2. If I now create a cookie with as expires value: current_timestamp + 31 * 86400 (expire in 31 days), how does the browser know the correct time? Are expire times converted to GMT values and then by the browser converted to the right timezone of the client? Or must they always be in GMT value?

Caching times probably have the same mechanism, if not please elaborate.

解决方案

Cookie expires headers are in a format that includes the timezone, so there is no ambiguity as to when the cookie will expire

http://www.cookiecentral.com/faq/#3.2

Set-Cookie: foo=bar; path=/; expires Mon, 09-Dec-2002 13:46:00 GMT

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