Firefox在毫秒转换中显示NaN到目前为止

Question

代码是：

var converted_timedate = Date.parse(tqaed_date); //tqaed_date=2015-08-03T14:44:39Z
var converted_int_timedate = parseInt(converted_timedate, 10); 
var convert_into_date = new Date(converted_int_timedate); 
var gettime_converteddate = convert_into_date.getTime() + ((-final_diff) * 1000 * 60); //final_diff=0

在Chrome中它正在运行，但在FF中显示NaN任何错误或建议？