Responsive notifications page using ReactJS

I recognize that this is not the best or most optimal solution, but I didn't want to spend too much time thinking about that and just did what I thought was ok at the moment, however any constructive criticism is welcome. The main issues I find with my solution is the big clutter in the Notification component that I could've split up, and the getConvertedTime function could be better by accounting for edge cases as well as changing the measurements ("minutes", "hours" etc.) to singular/plural when needed. And if there is anything else you notice that could be improved, please do tell, your feedback is appreciated.