Runs JavaScript on the Google Photos page to add a date label to all photos.
You will need some form of method to run arbitrary CSS and JavaScript in your browser. For Chrome, I use Stylus for CSS and CJS2 for JavaScript. (Though the latter has some strange bugs, I have yet to find a better one.)
Once you have these, simply add the JavaScript and CSS from the files in this repository and run them.
I didn't even bother licensing. Do whatever you want with it. All I ask is that you don't claim you made it.