calendar.dart

void main() {
  var today = new DateTime.now();
  var calendar = new List.generate(6, (i) => new List.filled(7, "  "));
  for (var i = 1, week = 0; i <= new DateTime(today.year, today.month + 1, 0).day; i++) {
    var day = new DateTime(today.year, today.month, i);
    calendar[week][day.weekday % 7] += i.toString();
    if (day.weekday == DateTime.SATURDAY) week++;
  }
  print(calendar.where((w) => w.any((d) => d.trim() != "")).map(
      (w) => w.map((d) => d.substring(d.length - 2)).join(" ")).join("\r\n"));
}