计算时间间隔

计算两个日期之间的差值。

基础计算

// 计算两个日期之间的毫秒差
function getTimeInterval(date1, date2) {
  return Math.abs(date2.getTime() - date1.getTime());
}

// 计算天数差
function getDaysDiff(date1, date2) {
  const msPerDay = 24 * 60 * 60 * 1000;
  return Math.floor(Math.abs(date2.getTime() - date1.getTime()) / msPerDay);
}

详细时间间隔

function getTimeIntervalDetail(start, end) {
  const diff = end.getTime() - start.getTime();
  const absDiff = Math.abs(diff);
  
  const days = Math.floor(absDiff / (1000 * 60 * 60 * 24));
  const hours = Math.floor((absDiff % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
  const minutes = Math.floor((absDiff % (1000 * 60 * 60)) / (1000 * 60));
  const seconds = Math.floor((absDiff % (1000 * 60)) / 1000);
  
  return {
    days,
    hours,
    minutes,
    seconds,
    totalMilliseconds: absDiff,
    isFuture: diff > 0
  };
}

// 使用
const start = new Date('2024-01-01');
const end = new Date('2024-12-31');
const result = getTimeIntervalDetail(start, end);

console.log(`相差 ${result.days} 天 ${result.hours} 小时 ${result.minutes} 分钟`);

倒计时/剩余时间

function getCountdown(targetDate) {
  const now = new Date();
  const diff = targetDate.getTime() - now.getTime();
  
  if (diff <= 0) {
    return { expired: true, message: '已过期' };
  }
  
  const days = Math.floor(diff / (1000 * 60 * 60 * 24));
  const hours = Math.floor((diff % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
  const minutes = Math.floor((diff % (1000 * 60 * 60)) / (1000 * 60));
  const seconds = Math.floor((diff % (1000 * 60)) / 1000);
  
  return {
    expired: false,
    days,
    hours,
    minutes,
    seconds,
    formatted: `${days}天${hours}小时${minutes}分钟${seconds}秒`
  };
}