Dart extension for DateTime sum/subtraction operations

main.dart

extension CopyWithAdditional on DateTime {
  DateTime copyWithAdditional({
    int years,
    int months = 0,
    int days = 0,
    int hours = 0,
    int minutes = 0,
    int seconds = 0,
    int milliseconds = 0,
    int microseconds = 0,
  }) {
    return DateTime(
      year + years,
      month + months,
      day + days,
      hour + hours,
      minute + minutes,
      second + seconds,
      millisecond + milliseconds,
      microsecond + microseconds,
    );
  }
}

void main() {
  print(DateTime.now().copyWithAdditional(years: 2, months: 14));
}