用 JavaScript 计算两个日期之间有多少天

我这里有两个日期，

const date1 = new Date("2024-02-01");
const date2 = new Date("2023-11-06");

然后将他们转换成时间戳：

const timestamp1 = date1.getTime();
const timestamp2 = date2.getTime();

再计算差值：

const diff = timestamp1 - timestamp2;

最后计算天数：

const days = Math.floor(diff / (1000 * 3600 * 24));

所以完整的代码是：

// 给定的两个日期
const date1 = new Date("2024-02-01");
const date2 = new Date("2023-11-06");

// 将两个日期都转换为时间戳(毫秒)
const timestamp1 = date1.getTime();
const timestamp2 = date2.getTime();

// 计算差值(毫秒)
const diff = timestamp1 - timestamp2;

// 把差值转换为天数
const days = Math.floor(diff / (1000 * 3600 * 24));

写成函数：

function calcDays(day1, day2) {
  const date1 = new Date(day1);
  const date2 = new Date(day2);
  const timestamp1 = date1.getTime();
  const timestamp2 = date2.getTime();
  const diff = timestamp1 - timestamp2;
  return Math.floor(diff / (1000 * 3600 * 24));
}