How can I modify cookies' lifetimes with Chrome (Mac)?

In Safari, when I wanted to avoid Cookies to expire (e.g. in order to stay logged in to MediaWiki for longer than 4 weeks), i could open the cookies file in a text editor and just change the expiry date.

Any idea how to do this with Chrome (on a Mac)?

The cookie file (http://stack开发者_运维知识库overflow.com/questions/4528208/google-chrome-cookie-storage) does not read very nice in a text editor...

Could you not install an extension to help you out like this one: https://chrome.google.com/webstore/detail/fngmhnnpilhplaeedifhccceomclgfbg?hl=en-GB