29. Kalkulator wieku i dat

function calculateAge(birthDate) {
  const birth = new Date(birthDate);
  const now = new Date();

  let years = now.getFullYear() - birth.getFullYear();
  let months = now.getMonth() - birth.getMonth();
  let days = now.getDate() - birth.getDate();

  if (days < 0) {
    months--;
    days += new Date(now.getFullYear(), now.getMonth(), 0).getDate();
  }
  if (months < 0) {
    years--;
    months += 12;
  }

  const totalDays = Math.floor((now - birth) / (1000 * 60 * 60 * 24));
  const totalHours = Math.floor((now - birth) / (1000 * 60 * 60));

  const nextBirthday = new Date(now.getFullYear(), birth.getMonth(), birth.getDate());
  if (nextBirthday <= now) nextBirthday.setFullYear(now.getFullYear() + 1);
  const daysToNextBirthday = Math.ceil((nextBirthday - now) / (1000 * 60 * 60 * 24));

  return { years, months, days, totalDays, totalHours, daysToNextBirthday };
}