JavaScript uses a zero-based index to identify each month in a year. This means, for JavaScript, January is represented by 0 instead of 1. Similarly, October is represented by 9 instead of 10.

Learn what the "this" keyword does in JavaScript in 100 seconds. And stay tuned for a few minutes of more advanced discussion after the credits.

There is, however, support for extensibility in the language. It’s also possible to run JavaScript and Hyperscript side-by-side, so that gives you latitude for gradual enhancement.