Find first and last DateTime of a week

find_week_start_or_end.dart

void main() {
  // Find first date and last date of CURRENT WEEK
  DateTime today = DateTime.now();
  print(findFirstDateOfTheWeek(today));
  print(findLastDateOfTheWeek(today));

  // Find first date and last date of any provided date
  DateTime date = DateTime.parse('2023-09-01');
  print(findFirstDateOfTheWeek(date));
  print(findLastDateOfTheWeek(date));
}

// return DateTime containing the first DateTime of a Week
DateTime findFirstDateOfTheWeek(DateTime dateTime) {
  return dateTime.subtract(Duration(days: dateTime.weekday - 1));
}

// return DateTime containing the last DateTime of a Week
DateTime findLastDateOfTheWeek(DateTime dateTime) {
  return dateTime.add(Duration(days: DateTime.daysPerWeek - dateTime.weekday));
}

/**
 * Other stuff
 * var now = new DateTime.now();
 * var now_1w = now.subtract(Duration(days: 7));
 * var now_1m = new DateTime(now.year, now.month-1, now.day);
 * var now_1y = new DateTime(now.year-1, now.month, now.day);
  
 * print(now_1w);
 **/