grafana/public/app/features/dashboard/timepicker/input_date.js

define([
  "angular",
  "lodash",
  "moment",
],function (angular, _, moment) {
  'use strict';

  angular.
    module("grafana.directives").
    directive('inputDatetime', function () {
    return {
      restrict: 'A',
      require: 'ngModel',
      link: function ($scope, $elem, attrs, ngModel) {
        var format = 'YYYY-MM-DD HH:mm:ss';

        var fromUser = function (text) {
          if (text.indexOf('now') !== -1) {
            return text;
          }
          var parsed;
          if ($scope.ctrl.isUtc) {
            parsed = moment.utc(text, format);
          } else {
            parsed = moment(text, format);
          }

          return parsed.isValid() ? parsed : undefined;
        };

        var toUser = function (currentValue) {
          if (moment.isMoment(currentValue)) {
            return currentValue.format(format);
          } else {
            return currentValue;
          }
        };

        ngModel.$parsers.push(fromUser);
        ngModel.$formatters.push(toUser);
      }
    };
  });
});