比较并更改日期格式，如今天、昨天、

function formatDate(date) {
  const now = new Date();
  const diff = now - date;

  // 比较日期差异
  const seconds = Math.floor(diff / 1000);
  const minutes = Math.floor(seconds / 60);
  const hours = Math.floor(minutes / 60);
  const days = Math.floor(hours / 24);
  const weeks = Math.floor(days / 7);
  const months = Math.floor(days / 30);
  const years = Math.floor(days / 365);

  if (seconds < 60) {
    return "刚刚";
  } else if (minutes < 60) {
    return `${minutes}分钟前`;
  } else if (hours < 24) {
    return `${hours}小时前`;
  } else if (days === 1) {
    return "昨天";
  } else if (days <= 7) {
    return `${days}天前`;
  } else if (weeks <= 4) {
    return `${weeks}周前`;
  } else if (months <= 12) {
    return `${months}个月前`;
  } else {
    return `${years}年前`;
  }
}

const date = new Date("2022-01-01");
const formattedDate = formatDate(date);
console.log(formattedDate); // 输出：几个月前