window.freezeMoment = (time, callback) ->
  #time = "#{time}Z" if typeof time is 'string' and time.slice(-1) isnt 'Z' # work with UTC dates?
  time = moment(time) unless time._isAMomentObject
  originalMomentNow = moment.now
  date = time.toDate()
  moment.now = -> date
  callback.call null, time
  moment.now = originalMomentNow
  time