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1.基础
// 获取中国标准时间
var date = new Date(); //Wed Apr 22 2020 14:41:58 GMT+0800 (中国标准时间)
//方法一
var timestamp = (new Date()).getTime();
console.log(timestamp); //1495302061441
//方法二
var timestamp2 = (new Date()).valueOf();
console.log(timestamp2); //1495302061441
//方法三
var timestamp3 = Date.parse(new Date());
console.log(timestamp3); //1495302061000
//第一种和第二种是获取了当前毫秒的时间戳
//最后一种获取的时间戳是把毫秒改成000显示
var year = date.getFullYear().toString(); //年
var month = date.getMonth() + 1; //月
var day = date.getDate(); //日
var hour = date.getHours(); //时
var minute = date.getMinutes(); //分
var second = date.getSeconds(); //秒
console.log(year, month, day, hour, minute, second) //2020 4 22 14 57 8
console.log(year + '-' + month + '-' + day + ' ' + hour + ':' + minute + ':' + second)
2. 获取当前时间转化格式为yyyy-MM-dd HH:mm:ss
console.log(year+'-'+month+'-'+day+' '+hour+':'+minute+':'+second)//2020-05-21 00:00:00
3. 获取指定日期时间戳(两种方式)
console.log((new Date("2020-05-21 00:00:00")).getTime()/1000)//getTime()获取的为毫秒
console.log((new Date("2020-05-21 00:00:00")).getTime()/1000)
3. 知道时间戳转化格式为yyyy-MM-dd HH:mm:ss
function timestampToTime(timestamp) {
console.log(timestamp.toString().length)
var numLength = timestamp.toString().length;
var date = '';
if(numLength==10){ //时间戳为10位需*1000，时间戳为13位的话不需乘1000
date = new Date(timestamp * 1000);
}else if(numLength==13){
date = new Date(timestamp);
}
var Y = date.getFullYear() + '-';
var M = (date.getMonth() + 1 < 10 ? '0' + (date.getMonth() + 1) : date.getMonth() + 1) + '-';
var D = date.getDate() + ' ';
var h = date.getHours() + ':';
var m = date.getMinutes() + ':';
var s = date.getSeconds();
return Y + M + D + h + m + s;
}
timestampToTime(1403058804);
console.log(timestampToTime(1589990400)); //2020-05-21 00:00:00
3. 日期格式转化为时间戳
var date = new Date('2020-05-21 00:00:00');
// 有三种方式获取
var time1 = date.getTime();
var time2 = date.valueOf();
var time3 = Date.parse(date);
console.log(time1);//1589990400000
console.log(time2);//1589990400000
console.log(time3);//1589990400000
4. 知道（比如，评论的发布时间戳/日期格式） 显示几小时前，几天前，几个月前
function getTs(time) {
var arr = time.split(/[- :]/),
_date = new Date(arr[0], arr[1] - 1, arr[2], arr[3], arr[4], arr[5]),
timeStr = Date.parse(_date)
return timeStr
}
function handlePublishTimeDesc(post_modified) {
// 拿到当前时间戳和发布时的时间戳，然后得出时间戳差
var curTime = new Date();
var postTime = new Date(post_modified);
//上面一行代码可以换成以下（兼容性的解决）
var timeDiff = curTime.getTime() - getTs(post_modified);
// 单位换算
var min = 60 * 1000;
var hour = min * 60;
var day = hour * 24;
var week = day * 7;
var month = week * 4;
var year = month * 12;
// 计算发布时间距离当前时间的周、天、时、分
var exceedyear = Math.floor(timeDiff / year);
var exceedmonth = Math.floor(timeDiff / month);
var exceedWeek = Math.floor(timeDiff / week);
var exceedDay = Math.floor(timeDiff / day);
var exceedHour = Math.floor(timeDiff / hour);
var exceedMin = Math.floor(timeDiff / min);
// 判断
if (exceedyear < 100 && exceedyear > 0) {
return exceedyear + '年前';
} else {
if (exceedmonth < 12 && exceedmonth > 0) {
return exceedmonth + '个月前';
} else {
if (exceedWeek < 4 && exceedWeek > 0) {
return exceedWeek + '周前';
} else {
if (exceedDay < 7 && exceedDay > 0) {
return exceedDay + '天前';
} else {
if (exceedHour < 24 && exceedHour > 0) {
return exceedHour + '小时前';
} else {
return exceedMin + '分钟前';
}
}
}
}
}
}
console.log(handlePublishTimeDesc("2020-03-26 15:33:00"))
4. 知道日期2020-03-26 15:33:00只显示2020-03-26
var timeStr = "2020-03-26 15:33:00";
console.log(timeStr.substring(0,10))；
console.log(timeStr.slice(0,10))；
