Very cool... would love to see a style method that works with material-ui and JSS... would just need a function that accepts a theme, and then use that theme combined with positional definitions `"& .subclass"` to target children... this way the styling can match material-ui while still keeping its' component structure... I haven't looked at the CSS or rendered markup to determine any of this, only know that it's possible.
edit: created feature request.
https://github.com/Adphorus/react-date-range/issues/347