Data-Driven Documents

https://d3js.org/
https://en.wikipedia.org/wiki/D3.js
D3.js (or just D3 for Data-Driven Documents) is a JavaScript library for producing dynamic, interactive data visualizations in web browsers

 
Other great javascript charting and graphics libraries:
http://www.jqplot.com/
http://www.highcharts.com/
http://techslides.com/50-javascript-charting-and-graphics-libraries
http://www.sitepoint.com/15-best-javascript-charting-libraries/ 
http://mikemcdearmon.com/portfolio/techposts/charting-libraries-using-d3

Comparison:
http://socialcompare.com/en/comparison/javascript-graphs-and-charts-libraries

Time Series Charts:
Free

• Google Charts
• Rickshaw
• C3.js
• plotly

Paid

• Highcharts
• AM Charts