gopro date formatter

var endDate = item.modifiedDate;
var duration = item.videoDuration;

var startDate = new Date(endDate - duration);

var output = "";

if (startDate.getDate() < 10) {
   output += "0";
}
output += startDate.getDate();

if (startDate.getMonth() < 10) {
   output += "0";
}
output += startDate.getMonth();

output += " - ";

if (startDate.getHours() < 10) {
   output += "0";
}
output += startDate.getHours();

if (startDate.getMinutes() < 10) {
   output += "0";
}
output += startDate.getMinutes();

return output;