Il nome datepicker era solo un'esempio per comprendere il tipo di calendario ..... sul sito originale non ho trovato nessuna documentazione in merito, allego link per il js e di seguito il css

www.pasqualedistasio.com

questo il link per visualizzare il file .js:
http://pasqualedistasio.com/exp/down...alendar.js.txt

questo il link per visualizzarne una demo:
http://pasqualedistasio.com/exp/calendar/

codice:
.calendar{
	border:1px solid #a3a3a3;
	font-family:Tahoma, Verdana, Arial, sans-serif;
	font-size:10px;
	color:#666666;
	background-color:#ffffff;
	padding:1px;
	width:218px;
}

.calendar > div.header{
	background-color: #B5C0CF;
	padding:2px;
	height:15px;
}
.calendar > div.header .date, .calendar > div.header .date_up{
	padding:1px 13px 1px 1px;
	margin: 0px 2px 0px 12px;
	color:#6F767F;
	font-weight:bold;
	cursor:pointer;
	background:url(images/down.gif) right 5px no-repeat;
}
.calendar > div.header .date_up{
	background:url(images/up.gif) right 4px no-repeat;
}

.calendar > div.main > table{
	border:0px;
	border-spacing:1px;
}
.calendar > div.main > table th{
	text-align:center;
	width:30px;
	padding:4px 0px 4px 0px;
}
.calendar > div.main > table td{
	text-align:center;
	padding:4px 0px 4px 0px;
}

.calendar > div.main > table td.day_on{
	background-color:#B5C0CF;
	cursor:pointer;
}
.calendar > div.main > table td.day_selected{
	background-color:#D4D8DE;
}
.calendar > div.main > table td.day_disabled{
	color:#cccccc;
}

.calendar > div.inc_dec{
	border:1px solid #B3B8BF;
}
.calendar > div.inc_dec > table{
	border-spacing:1px;
	background-color: #f6f6f6;
}
.calendar > div.inc_dec > table th{
	background-color: #D1D7DF;
	border-bottom:1px solid #C2C8CF;
	color:#6F767F;
	padding: 1px;
}
.calendar > div.inc_dec > table th .years{
	width:94px;
}

.calendar > div.inc_dec > table td{
	text-align:center;
	width:42px;
	cursor:pointer;
	padding:3px 0px;
}
.calendar > div.inc_dec > table td.month_on{
	font-weight:bold;
}
.calendar > div.inc_dec > table td.month_selected{
	font-weight:bold;
	color:#9BABBF;
}

.calendar > div.footer{
	text-align:center;
	margin-top:1px;
	padding:3px;
	background-color:#dfdfdf;
}
.calendar > div.footer > div{
	cursor: pointer;
}

.calendar > div.time{
	text-align:center;
	margin-top:1px;
	padding:2px;
	background-color:#e3e3e3;
}

.calendar > div.time > div{
	width:104px;
	margin:0px auto;
}
.calendar > div.time > div > div{
	background-color:#ECECEC;
	border-top:1px solid #D1D1D1;
	border-bottom:1px solid #D1D1D1;
	color:#999999;
	width:20px;
	height: 15px;
	text-align:center;
	padding-top:2px;
}