js中date类型的数据

// 创建一个表示当前日期和时间的 Date 对象
let now = new Date();
console.log(now); // 输出类似 "Tue Jun 21 2023 10:30:15 GMT+0800 (China Standard Time)"

// 获取年份
let year = now.getFullYear();
console.log(year); // 输出 2023

// 设置新的日期和时间
let specificDate = new Date(2023, 5, 21, 12, 0, 0); // 注意月份是从0开始的，所以6月是5
console.log(specificDate); // 输出 "Tue Jun 21 2023 12:00:00 GMT+0800 (China Standard Time)"

function formatDate(date) {
    let year = date.getFullYear();
    let month = ('0' + (date.getMonth() + 1)).slice(-2); // 月份加1，并补零
    let day = ('0' + date.getDate()).slice(-2);
    let hours = ('0' + date.getHours()).slice(-2);
    let minutes = ('0' + date.getMinutes()).slice(-2);
    let seconds = ('0' + date.getSeconds()).slice(-2);
    return `${year}-${month}-${day} ${hours}:${minutes}:${seconds}`;
}

let formattedDate = formatDate(now);
console.log(formattedDate); // 输出 "2023-06-21 10:30:15"

// 获取 UTC 时间
let utcDate = new Date(Date.UTC(2023, 5, 21, 12, 0, 0));
console.log(utcDate); // 输出 "Tue Jun 21 2023 12:00:00 GMT+0000 (Coordinated Universal Time)"

// 转换为本地时间
let localDate = new Date(utcDate.getTime() + utcDate.getTimezoneOffset() * 60000);
console.log(localDate); // 输出根据本地时区调整后的时间