js获取日期对应的星期几

function getDayOfWeek(date) {
  const days = ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'];
  return days[date.getDay()];
}

// 示例
const today = new Date();
console.log(getDayOfWeek(today)); // 输出当前日期对应的星期几

function getDayOfWeekIntl(date) {
  const options = { weekday: 'long' };
  return new Intl.DateTimeFormat('zh-CN', options).format(date);
}

// 示例
const today = new Date();
console.log(getDayOfWeekIntl(today)); // 输出当前日期对应的星期几（中文）

function getDayOfWeekManual(year, month, day) {
  if (month < 3) {
    month += 12;
    year -= 1;
  }
  const K = year % 100;
  const J = Math.floor(year / 100);
  const f = day + Math.floor((13 * (month + 1)) / 5) + K + Math.floor(K / 4) + Math.floor(J / 4) - 2 * J;
  const dayOfWeek = (f + 5) % 7; // 调整为0表示星期日
  const days = ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'];
  return days[dayOfWeek];
}

// 示例
const today = new Date();
console.log(getDayOfWeekManual(today.getFullYear(), today.getMonth() + 1, today.getDate()));