fp2.js

// birth-day/component.js
import Ember from 'ember';
import moment from 'moment';

const { 
  Component, 
  computed,
  get
} = Ember;

export default Component.extend({
  // ...
  isBirthday: computed('birthDate', {
    get() {
      let today = moment();
      let birthDate = moment(get(this, 'birthDate'));

      return (today.month() === birthDate.month()) && 
        (today.day() === birthDate.day());
    }
  })
});