I have a web service that is returning a date as the following string: /Date(1377907200000)/ I use MomentJS to parse this to a moment object. moment(“/Date(1377907200000)/”) => Fri Aug 30 2013 20:00:00 GMT-0400 All of that is fine. But when I call unix() on the object I am given the value 1377907200. This, however, corresponds to Fri Jan 16 1970