datetime.parse2

datetime_parse2.dart

void main() {
  var s = 'Thu Jan 32 23:39:59 2021+444';
  var t = parse2(s);
  print(t);
}

DateTime parse2(String formattedString) {
  final re = RegExp(r'^(\w{3}) ' // weekday
                    r'(\w{3}) ' // month
                    r'(\d{2}) ' // day in month
                    r'(\d{2}):(\d{2}):(\d{2}) ' //hh:mm:ss
                    r'(\d{4})' // year
                    r'(\+(\d+))?$' // millisec
                   );
  final match = re.firstMatch(formattedString);
  
  if (match != null) {
    return DateTime(
      int.tryParse(match[7].toString()) ?? 0,
      fromMMMtoMM(match[2].toString()),
      int.tryParse(match[3].toString()) ?? 0,
      int.tryParse(match[4].toString()) ?? 0,
      int.tryParse(match[5].toString()) ?? 0,
      int.tryParse(match[6].toString()) ?? 0,
      int.tryParse(match[9].toString()) ?? 0
    );
  } else {
    throw FormatException('Invalid date format', formattedString);
  }
}

int fromMMMtoMM(String mmm) {
  switch (mmm.toLowerCase()) {
    case 'jan':
      return 01;
    case 'feb':
      return 02;
    case 'mar':
      return 03;
    case 'apr':
      return 04;
    case 'may':
      return 05;
    case 'jun':
      return 06;
    case 'jul':
      return 07;
    case 'aug':
      return 08;
    case 'sep':
      return 09;
    case 'oct':
      return 10;
    case 'nov':
      return 11;
    case 'dec':
      return 12;
  }
  throw FormatException('Invalid month format', mmm);
}