//Require it
var PickerManager= require("nativescript-timedatepicker");
//Create a callback function
var mCallback = function (result) {
  if (result) {
    alert("the time is "+result);
  }
};
//Initialize the PickerManager (.init(yourCallback, title, initialDate))
PickerManager.init(mCallback,null,null);
//Show the dialog
PickerManager.showTimePickerDialog();

//If you want to convert the string into a js Date I recomend to use moment.js
  var scheduleMoment = moment(result, "DD MM YYYY HH:mm z");
  var scheduleDate = scheduleMoment.toDate();