How do I output an ISO 8601 formatted string in JavaScript?

Question

I have a Date object. How do I render the title portion of the following snippet?

Answer 1

The question asked was ISO format with reduced precision. Voila:

 new Date().toISOString().slice(0, 19) + 'Z'
 // '2014-10-23T13:18:06Z'

Assuming the trailing Z is wanted, otherwise just omit.