摘要：獲取定制時(shí)間戳的方法返回?cái)?shù)值的單位是毫秒。返回指定日期減去時(shí)間間隔后的具體日期返回返回指定日期為全年的第幾天日期二將時(shí)間戳轉(zhuǎn)為普通日期時(shí)間格式當(dāng)前時(shí)間戳將時(shí)間戳轉(zhuǎn)為日期時(shí)間格式

PHP、JavaScript、MySQL操作時(shí)間

關(guān)于時(shí)間的那些事

PHP篇

PHP中時(shí)間操作單位是秒

一、將時(shí)間戳轉(zhuǎn)為普通日期格式

//當(dāng)前時(shí)間戳
time();    
//當(dāng)前時(shí)間格式
date("Y-m-d H:i:s",time());
//昨天時(shí)間格式
date("Y-m-d,H:i:s",time()-3600*24);

二、將普通日期格式轉(zhuǎn)為時(shí)間戳

//將日期格式轉(zhuǎn)為時(shí)間戳
strtotime("now"); //當(dāng)前時(shí)間戳
strtotime("last Monday");    //上個(gè)星期一的時(shí)間戳
strtotime("+1 day");    //一天后的時(shí)間戳
strtotime("2017-12-25");    //1514131200

JavaScript篇

js中時(shí)間操作單位是毫秒

一、js將時(shí)間轉(zhuǎn)換成時(shí)間戳

js獲取當(dāng)前時(shí)間戳的方法

var timestamp1 = Date.parse(new Date());
var timestamp2 = (new Date()).valueOf();
var timestamp3 = new Date().getTime();

第一種：獲取的時(shí)間戳是把毫秒改成000顯示，第二種和第三種是獲取了當(dāng)前毫秒的時(shí)間戳。

js獲取定制時(shí)間戳的方法

var oldTime = (new Date("2017-12-25 08:00:20")).getTime();

 getTime()返回?cái)?shù)值的單位是毫秒。

二、js將時(shí)間戳轉(zhuǎn)為普通日期格式

Date toLocaleString方法

function getLocalTime(nS) {
return new Date(parseInt(nS)).toLocaleString().replace(/:d{1,2}$/,"");
}

parseInt() 函數(shù)可解析一個(gè)字符串，并返回一個(gè)整數(shù)

toLocaleString() 方法可根據(jù)本地時(shí)間把 Date 對(duì)象轉(zhuǎn)換為字符串，并返回結(jié)果。

replace(/:d{1,2}$/,"")驗(yàn)證替換以：開(kāi)始有一位或二位數(shù)字的結(jié)束字符串，就是秒；替換為空

Date 屬性方法

function add0(m){return m<10?"0"+m:m }
function format(shijianchuo)
{

//shijianchuo是整數(shù)，否則要parseInt轉(zhuǎn)換
var time = new Date(shijianchuo);
var y = time.getFullYear();
var m = time.getMonth()+1;
var d = time.getDate();
var h = time.getHours();
var mm = time.getMinutes();
var s = time.getSeconds();
return y+"-"+add0(m)+"-"+add0(d)+" "+add0(h)+":"+add0(mm)+":"+add0(s);

}

三、封裝的時(shí)間格式器

/**
* 和PHP一樣的時(shí)間戳格式化函數(shù)
* @param {string} format 格式
* @param {int} timestamp 要格式化的時(shí)間 默認(rèn)為當(dāng)前時(shí)間
* @return {string} 格式化的時(shí)間字符串
*/
function date(format, timestamp){
    var a, jsdate=((timestamp) ? new Date(timestamp*1000) : new Date());
    var pad = function(n, c){
        if((n = n + "").length < c){
            return new Array(++c - n.length).join("0") + n;
        } else {
            return n;
        }
    };
    var txt_weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
    var txt_ordin = {1:"st", 2:"nd", 3:"rd", 21:"st", 22:"nd", 23:"rd", 31:"st"};
    var txt_months = ["", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
    var f = {
    // Day
        d: function(){return pad(f.j(), 2)},
        D: function(){return f.l().substr(0,3)},
        j: function(){return jsdate.getDate()},
        l: function(){return txt_weekdays[f.w()]},
        N: function(){return f.w() + 1},
        S: function(){return txt_ordin[f.j()] ? txt_ordin[f.j()] : "th"},
        w: function(){return jsdate.getDay()},
        z: function(){return (jsdate - new Date(jsdate.getFullYear() + "/1/1")) / 864e5 >> 0},
    // Week
        W: function(){
            var a = f.z(), b = 364 + f.L() - a;
            var nd2, nd = (new Date(jsdate.getFullYear() + "/1/1").getDay() || 7) - 1;
            if(b <= 2 && ((jsdate.getDay() || 7) - 1) <= 2 - b){
                return 1;
            } else{
                if(a <= 2 && nd >= 4 && a >= (6 - nd)){
                    nd2 = new Date(jsdate.getFullYear() - 1 + "/12/31");
                    return date("W", Math.round(nd2.getTime()/1000));
                } else{
                    return (1 + (nd <= 3 ? ((a + nd) / 7) : (a - (7 - nd)) / 7) >> 0);
                }
            }
        },
    // Month
        F: function(){return txt_months[f.n()]},
        m: function(){return pad(f.n(), 2)},
        M: function(){return f.F().substr(0,3)},
        n: function(){return jsdate.getMonth() + 1},
        t: function(){
            var n;
            if( (n = jsdate.getMonth() + 1) == 2 ){
                return 28 + f.L();
            } else{
                if( n & 1 && n < 8 || !(n & 1) && n > 7 ){
                    return 31;
                } else{
                    return 30;
                }
            }
        },
    // Year
        L: function(){var y = f.Y();return (!(y & 3) && (y % 1e2 || !(y % 4e2))) ? 1 : 0},
        //o not supported yet
        Y: function(){return jsdate.getFullYear()},
        y: function(){return (jsdate.getFullYear() + "").slice(2)},
        // Time
        a: function(){return jsdate.getHours() > 11 ? "pm" : "am"},
        A: function(){return f.a().toUpperCase()},
        B: function(){
    // peter paul koch:
            var off = (jsdate.getTimezoneOffset() + 60)*60;
            var theSeconds = (jsdate.getHours() * 3600) + (jsdate.getMinutes() * 60) + jsdate.getSeconds() + off;
            var beat = Math.floor(theSeconds/86.4);
            if (beat > 1000) beat -= 1000;
            if (beat < 0) beat += 1000;
            if ((String(beat)).length == 1) beat = "00"+beat;
            if ((String(beat)).length == 2) beat = "0"+beat;
            return beat;
        },
        g: function(){return jsdate.getHours() % 12 || 12},
        G: function(){return jsdate.getHours()},
        h: function(){return pad(f.g(), 2)},
        H: function(){return pad(jsdate.getHours(), 2)},
        i: function(){return pad(jsdate.getMinutes(), 2)},
        s: function(){return pad(jsdate.getSeconds(), 2)},
    //u not supported yet
    // Timezone
    //e not supported yet
    //I not supported yet
        O: function(){
            var t = pad(Math.abs(jsdate.getTimezoneOffset()/60*100), 4);
            if (jsdate.getTimezoneOffset() > 0) t = "-" + t; else t = "+" + t;
            return t;
        },
        P: function(){var O = f.O();return (O.substr(0, 3) + ":" + O.substr(3, 2))},
    //T not supported yet
    //Z not supported yet
    // Full Date/Time
        c: function(){return f.Y() + "-" + f.m() + "-" + f.d() + "T" + f.h() + ":" + f.i() + ":" + f.s() + f.P()},
    //r not supported yet
        U: function(){return Math.round(jsdate.getTime()/1000)}
    };
    return format.replace(/[]?([a-zA-Z])/g, function(t, s){
        if( t!=s ){
        // escaped
            ret = s;
        } else if( f[s] ){
        // a date function exists
            ret = f[s]();
        } else{
        // nothing special
            ret = s;
        }
            return ret;
    });
}

調(diào)用方法 能夠很方便的將時(shí)間戳(秒)轉(zhuǎn)換成日期的格式，如：

date("Y-m-d","1514093093"); 轉(zhuǎn)為2017-12-24
date("Y-m-d H:i:s","1514093110");轉(zhuǎn)為2017-12-24 13:25:10

MySQL篇

MySQL的時(shí)間單位是秒

一、普通時(shí)間日期格式相關(guān)函數(shù)

獲取當(dāng)前普通時(shí)間格式

#獲取當(dāng)前時(shí)間日期
select now();    #2017-12-24 14:06:12
#當(dāng)前日期
select curdate();  #2017-12-24
#當(dāng)前時(shí)間
select curtime(); #14:06:12

獲取指定時(shí)間的部分

#返回日期時(shí)間的日期部分
date()
#返回日期的時(shí)間部分
time()
#返回日期的年份部分
year()

#給定一個(gè)日期date, 返回一個(gè)天數(shù) (從年份0開(kāi)始的天數(shù) )。
TO_DAYS()    
#求兩個(gè)日期的差，返回天數(shù)
datediff("20171225","20170101")    
datediff("2017-12-25","2017-01-01")

時(shí)間間隔

#向指定日期添加時(shí)間間隔。
date_add("20171224",interval 1 day);    #返回2017-12-25

#指定日期減去時(shí)間間隔后的具體日期
date_sub("20171224",interval 9 day)    #f返回2017-12-15

#返回指定日期為全年的第幾天
dayofyear(日期)：

二、將時(shí)間戳轉(zhuǎn)為普通日期時(shí)間格式

#當(dāng)前時(shí)間戳
unix_timestamp()
#將時(shí)間戳轉(zhuǎn)為日期時(shí)間格式
select FROM_UNIXTIME(1514131200);    #2017-12-25 00:00:00