Simple DatePicker calendar_time and date implemented in javascript

var DatePicker = function () {
var $ = function (i) {return document.getElementById(i)},
addEvent = function (o, e, f) {o.addEventListener ? o.addEventListener(e, f, false) : o.attachEvent('on' e, function(){f.call(o)})},
getPos = function (el) {
for (var pos = {x:0, y:0}; el; el = el.offsetParent) {
pos.x = el.offsetLeft;
pos.y = el.offsetTop;
}
return pos;
}

var init = function (n, config) {
window[n] = this;
Date.prototype._fd = function () {var d = new Date(this); d.setDate(1); return d.getDay()};
Date.prototype._fc = function () {var d1 = new Date(this), d2 = new Date(this); d1.setDate(1); d2.setDate(1); d2.setMonth(d2.getMonth() 1); return (d2-d1)/86400000;};
this.n = n;
this.config = config;
this.D = new Date;
this.el = $(config.inputId);
this.el.title = this.n 'DatePicker';

this.update();
this.bind();
}
init.prototype = {

update : function (y, m) {
var con = [], week = ['Su','Mo','Tu','We','Th','Fr','Sa'], D = this.D, _this = this;
fn = function (a, b) {return '' b ''},
_html = '';
y && D.setYear(D.getFullYear() y);
m && D.setMonth(D.getMonth() m);
var year = D.getFullYear(), month = D.getMonth() 1, date = D.getDate();
for (var i=0; i' week[i] '');
for (var i=0; i ');
for (var i=0; i' (i 1) '');
var toend = con.length%7;
if (toend != 0) for (var i=0; i<7-toend; i ) con.push('');
_html = '' fn("-1, null", "<<") fn("null, -1", "<") '' fn("null, 1", ">") fn("1, null", ">>") '';
for (var i=0; i' : i%7==0 ? '' : '') con[i] (i == con.length-1 ? '' : '');
!!this.box ? this.box.innerHTML = _html : this.createBox(_html);
},
fillInput : function (y, m, d) {
var s = this.config.seprator || '/';
this.el.value = y s m s d;
this.box.style.display = 'none';
},
show : function () {
var s = this.box.style, is = this.mask.style;
s['left'] = is['left'] = getPos(this.el).x 'px';
s['top'] = is['top'] = getPos(this.el).y this.el.offsetHeight 'px';
s['display'] = is['display'] = 'block';
is['width'] = this.box.offsetWidth - 2 'px';
is['height'] = this.box.offsetHeight - 2 'px';
},
hide : function () {
this.box.style.display = 'none';
this.mask.style.display = 'none';
},
bind : function () {
var _this = this;
addEvent(document, 'click', function (e) {
e = e || window.event;
var t = e.target || e.srcElement;
if (t.title != _this.n 'DatePicker') {_this.hide()} else {_this.show()}
})
},
createBox : function (html) {
var box = this.box = document.createElement('div'), mask = this.mask = document.createElement('iframe');
box.className = this.config.className || 'datepicker';
mask.src = 'javascript:false';
mask.frameBorder = 0;
box.style.cssText = 'position:absolute;display:none;z-index:9999';
mask.style.cssText = 'position:absolute;display:none;z-index:9998';
box.title = this.n 'DatePicker';
box.innerHTML = html;
document.body.appendChild(box);
document.body.appendChild(mask);

return box;
}
}

return init;
}();

调用方式：

第一个参数：实例名，
第二个参数一个对象字面量，包括输入框的id（必须），弹出日历box的className，日期样式的分隔符如‘-'，‘/'，等。后两个可省略，默认值‘datepicker'，‘/'。

' year '/' month '/' date '