Converts: hours; minutes; seconds, into milliseconds since midnight.

TimeConverter.dart

void main() {
  print(fromTime(13, 30));
}

int fromTime(int hours, [int minutes = 0, int seconds = 0]) {
  var tot = hours * 60 * 60;
  tot += (minutes * 60);
  tot += seconds;
  return tot * 1000;
}