By using this :
Text(new DateTime.fromMillisecondsSinceEpoch(values[index][\"start_time\"]*1000).toString(),
I am getting the ty
You can use date_format plugin available here https://pub.dartlang.org/packages/date_format
date_format
Then to convert,
formatDate(DateTime.now(), [dd, '/', mm, '/', yyyy, ' ', HH, ':', nn])