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(),
    }
})

响应：

{
  "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在获取规范的forbidden header names中列出。

  

这些都是禁止的，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