Update April 2017:
As of version 2.13.0, Moment includes a typescript definition file. https://momentjs.com/docs/#/use-it/typescript/
Just install it with npm, in your console type
npm install --save moment
And then in your Angular app, import is as easy as this:
import * as moment from 'moment';
That’s it, you get full Typescript support!
Bonus edit: To type a variable or property as Moment
in Typescript you can do this e.g.:
let myMoment: moment.Moment = moment("someDate");