class LessonSlot {
  const LessonSlot(this.period, this.startMinute, this.endMinute);
  final int period, startMinute, endMinute;
}

const lessonSlots = [
  LessonSlot(1, 510, 555),
  LessonSlot(2, 560, 605),
  LessonSlot(3, 620, 665),
  LessonSlot(4, 670, 715),
  LessonSlot(5, 870, 915),
  LessonSlot(6, 920, 965),
  LessonSlot(7, 980, 1025),
  LessonSlot(8, 1030, 1075),
  LessonSlot(9, 1170, 1215),
  LessonSlot(10, 1220, 1265),
  LessonSlot(11, 1270, 1315),
  LessonSlot(12, 1320, 1365),
];
String minuteLabel(int minute) =>
    '${(minute ~/ 60).toString().padLeft(2, '0')}:${(minute % 60).toString().padLeft(2, '0')}';