gistfile1.js

<input class="form-control" type="text" unix-time-directive="timeFormat" ng-model="t.pickup_time">

.directive('unixTimeDirective', function(moment) {
    function link(scope, element, attrs, ngModelController) {
      var format = scope.$eval(attrs.unixTimeDirective);

      scope.$watch(attrs.unixTimeDirective, function(value) {
        format = value;
      });
      ngModelController.$parsers.push(function(data) {
        return moment(data, format).unix();
      });
      ngModelController.$formatters.push(function(data) {
        return moment.unix(data).format(format);
      });