js 根据周数 计算日期

function getWeekRange(year, week) {
    const firstDayOfYear = new Date(year, 0, 1);
    const dayOfWeek = firstDayOfYear.getDay() || 7;
    const startOfYearOffset = firstDayOfYear.getDate() - dayOfWeek;
    const totalDays = startOfYearOffset + (week - 1) * 7;
    const weekStart = new Date(year, 0, totalDays + 1);
    const weekEnd = new Date(weekStart);
    weekEnd.setDate(weekEnd.getDate() + 6);
    return { start: weekStart, end: weekEnd };
}

// 示例用法
const year = 2023;
const week = 40;
const weekRange = getWeekRange(year, week);
console.log(`Week ${week} of ${year} starts on ${weekRange.start.toDateString()} and ends on ${weekRange.end.toDateString()}`);