I briefly looked at all the charting libraries on this list here: https://hackernoon.com/9-best-javascript-charting-libraries-...
If I were doing this project over again, I'd probably use [Chartist](https://gionkunz.github.io/chartist-js/) as out of all the libraries I looked at, it seems to be the easiest to get up and running.
While charts.js is a little more interactive, it was a little painful to get up and running.
The time slider is just an input slider some jQuery I wrote that dynamically loads up a new dataset and calls the redraw function in charts.js to load up a new chart.
Overall, as someone with entry-level experience in both manipulating data and web development, I found the overall process to be a little rough at first, but it got a lot better once I got the hang of the library.
In total, the entire website took me about a week, with 2 hours of work every day. So something like 15 hours, total?