Human readable date strings replace all timestamps in a page with a single click without going to the console and copy-pasting from epoch to a new Date() for each one..... click again and it toggles back so you can review the original timestamp!
Off the top of your head, was 1439580577271 last Thursday? Or if you have a JSON with fifty items in a list, are they basically daily or weekly or what? This will solve your problems :) It is designed to work with an existing extension such as JSONviewer (cross promotion! They are great) just like in the screenshots.
The E is for easy, excellent, elephant, whatever you like.