gistfile1.js

ko.bindingHandlers.dateString = {
    update: function (element, valueAccessor, allBindingsAccessor, viewModel) {
        var value = valueAccessor(),
            allBindings = allBindingsAccessor();
        var valueUnwrapped = ko.utils.unwrapObservable(value);        
        var pattern = allBindings.datePattern || 'mmmm d, yyyy';
        if (valueUnwrapped == undefined || valueUnwrapped == null) {
            $(element).text("");
        }
        else {
            var date = moment(valueUnwrapped, "YYYY-MM-DDTHH:mm:ss"); //new Date(Date.fromISO(valueUnwrapped));
            $(element).text(moment(date).format(pattern));
        }
    }
}