This project used React & JSX.
Given that I allocated one day for this project, there are quite a few rough spots. The options page has been left have finished, and the naming convensions for variables, files, class names etc aren't as consistent as I would have liked.
I accomplished all the features with the exception of creating new events. This isn't much of a problem for testing however since I make liberal use of a fake data generator. The view for a single day isn't pretty, though the events do have fun names and bright colors.
The calendar can be found at '/calendar'. This does require a static file server to get the url endpoints correct.
To run this project, you can npm -g install static-server, followed by navigating to the public directory where you will then run static-server. The server will let you know which localhost port to connect to.
If you want to dig deep into the code, you will need Node v6. npm install will handle the rest. npm build --release to build, and npm start to run the dev server.
NOTE: I started the project using Yeoman's React Static boilerplate (https://github.com/kriasoft/react-static-boilerplate#readme) which is was really heavy on the asset pipeline, but really came with very little to offer in terms of web page implementation.