How to get cookie's expire time

In web development, retrieving the expiration time of a cookie is not a straightforward process because the browser's JavaScript API does not provide a direct method to obtain the expiration time of stored cookies. However, there are several methods to indirectly retrieve or estimate the expiration time of a cookie:

1. Server-Side Setting and Sending to Client: When a server creates a cookie and sends it to the client via an HTTP response, it can specify the Expires attribute or Max-Age attribute in the Set-Cookie header. If you have access to server logs or can inspect network requests through developer tools, you can find the Set-Cookie header and read the Expires or Max-Age attribute from it.

   For example, a Set-Cookie header might look like this:

   shell
   Set-Cookie: sessionId=abc123; Expires=Wed, 09 Jun 2021 10:18:14 GMT

   If you are a server-side developer, you can record the expiration time when creating the cookie and access it when needed.

2. Client-Side JavaScript Recording at Creation Time: When you create a cookie using JavaScript on the client side, you may choose to store the expiration time elsewhere, such as in localStorage or sessionStorage.

   javascript
   const expireDate = new Date();
   expireDate.setTime(expireDate.getTime() + (10 * 60 * 1000)); // Set to expire in 10 minutes
   document.cookie = "username=JohnDoe; expires=" + expireDate.toUTCString();
   
   localStorage.setItem('usernameExpires', expireDate.getTime());

   Later, you can retrieve the expiration time by reading the value from localStorage.

3. Third-Party Libraries: Some third-party JavaScript libraries provide functionality to read cookies and parse their expiration time. If you are using such a library in your project, you can obtain the cookie's expiration time according to the library's documentation.

Note that if the cookie is set by the server and you do not have server logs or other recording methods, it is not possible to directly retrieve the expiration time from client-side JavaScript. In such cases, you may need to consider using a server-side API to provide this information or record relevant information at the time of setting the cookie.