js 时间戳 日期格式化 函数

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(){
t = f.l(); return t.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(){
t = f.F(); return t.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;
});
}

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