knockout.js datetimepicker bindingHandler

ko.bindingHandlers.datetimepicker.js

ko.bindingHandlers.datetimepicker = {
        init: function (element, valueAccessor, allBindingsAccessor) {
          /*! version : 4.17.45
           =========================================================
           bootstrap-datetimejs
           https://github.com/Eonasdan/bootstrap-datetimepicker
           =========================================================
          */
            $(element).datetimepicker({
                icons: {
                    time: "fa fa-clock-o",
                    date: "fa fa-calendar",
                    up: "fa fa-arrow-up",
                    down: "fa fa-arrow-down"
                },
                useCurrent: false,
                locale: lang
            })

            ko.utils.registerEventHandler(element, "dp.change", function (event) {
                var value = valueAccessor();
                if (ko.isObservable(value)) {
                    if (event.date && !(event.date instanceof Date)) {
                        if (!event.date._isUTC)
                            event.date = event.date.add(event.date.utcOffset(), 'm');
                        value(event.date.toDate());
                    } else if (event.date == null || event.date == false) {
                        value(null);
                    }
                }
            });

            var value = ko.utils.unwrapObservable(valueAccessor());
            if (value) {
                value = moment(value).isValid() ? moment.utc(value) : moment(value, "L LT");
            }
            $(element).data("DateTimePicker").date(value);

            ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
                var picker = $(element).data("DateTimePicker");
                if (picker) {
                    picker.destroy();
                }
            });
        },
        update: function (element, valueAccessor, allBindings, viewModel, bindingContext) {           
        }
    };