Angularjs: Timestamp To Formatted UTC Time With Date Helper

I'm looking for idea how to format unix timestamp with AngularJS date helper? In official documentation, there is only explanation for string inputs (If no timezone is specified in

Solution 1:

I've found some solution with custom filter and momentjs library:

app.filter('moment', function() {  
    return function(input, format) {  
        return moment(parseInt(input)).utc().format(format);  
    };  
});