为什么浏览器不发送我的显式“Date”标头？

Question

代码示例：

fetch('https://httpbin.org/get', {
    'headers': {
        'Date': (new Date()).toUTCString(),
    }
})

回复：

{
  "args": {}, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate, br", 
    "Accept-Language": "en-US,en;q=0.9", 
    "Connection": "close", 
    "Host": "httpbin.org", 
    "Origin": "http://localhost:8000", 
    "Referer": "http://localhost:8000/", 
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36 OPR/58.0.3135.53"
  }, 
  "origin": "146.120.13.65", 
  "url": "https://httpbin.org/get"
}

Answer 1

Date被列在获取规范中的禁止标头名称中。

这些是被禁止的，因此用户代理仍然可以完全控制它们。

• Accept-Charset

• Accept-Encoding

• Access-Control-Request-Headers

• Access-Control-Request-Method

• Connection

• Content-Length

• Cookie

• Cookie2

• Date

• DNT

• Expect

• Host

• Keep-Alive

• Origin

• Referer

• TE

• Trailer

• Transfer-Encoding

• Upgrade

• Via