firstISOWeek property

Week firstISOWeek

Get the first ISO week of the year

Implementation

Week get firstISOWeek {
  final yearOfWeek = startOfYear.yearOfISOWeek;
  if (yearOfWeek == year) {
    // yearOfWeek is the same year, return the start of week for 1st of Jan
    return Week.isoWeek(startOfYear);
  } else {
    // yearOfWeek must be previous year, return the next week instead
    return Week.isoWeek(startOfYear.addWeeks(1));
  }
}