计算两个日期之间的天数js

function getDaysBetweenDates(date1, date2) {
    // 将日期转换为时间戳
    const timestamp1 = new Date(date1).getTime();
    const timestamp2 = new Date(date2).getTime();

    // 计算两个时间戳之间的差值（毫秒）
    const diffInMilliseconds = Math.abs(timestamp2 - timestamp1);

    // 将毫秒转换为天数
    const diffInDays = Math.ceil(diffInMilliseconds / (1000 * 60 * 60 * 24));

    return diffInDays;
}

// 示例使用
const date1 = '2023-10-01';
const date2 = '2023-10-10';
console.log(getDaysBetweenDates(date1, date2)); // 输出: 9

function getDaysBetweenDatesUTC(date1, date2) {
    const timestamp1 = new Date(date1).getTime();
    const timestamp2 = new Date(date2).getTime();
    const diffInMilliseconds = Math.abs(timestamp2 - timestamp1);
    const diffInDays = Math.ceil(diffInMilliseconds / (1000 * 60 * 60 * 24));
    return diffInDays;
}

const date1UTC = '2023-10-01T00:00:00Z';
const date2UTC = '2023-10-10T00:00:00Z';
console.log(getDaysBetweenDatesUTC(date1UTC, date2UTC)); // 输出: 9