var LunarDaysOfMonth = new Array
(
0xd4a8, 0xd4a0, 0xda50, 0x5aa8, 0x56a0, 0xaad8, 0x25d0, 0x92d0, 0xc958, 0xa950, // 2001-2010
0xb4a0, 0xb550, 0xb550, 0x55a8, 0x4ba0, 0xa5b0, 0x52b8, 0x52b0, 0xa930, 0x74a8, // 2011-2020
0x6aa0, 0xad50, 0x4da8, 0x4b60, 0x9570, 0xa4e0, 0xd260, 0xe930, 0xd530, 0x5aa0, // 2021-2030
0x6b50, 0x96d0, 0x4ae8, 0x4ad0, 0xa4d0, 0xd258, 0xd250, 0xd520, 0xdaa0, 0xb5a0, // 2031-2040
0x56d0, 0x4ad8, 0x49b0, 0xa4b8, 0xa4b0, 0xaa50, 0xb528, 0x6d20, 0xada0, 0x55b0 // 2041-2050
);

// 数组LunarLeapYear存放农历2001年到2050年闰月的月份，如没有则为0，从高到低，每字节存两年
var LunarLeapYear = new Array
(
0x40, 0x02, 0x07, 0x00, 0x50, // 2001-2010
0x04, 0x09, 0x00, 0x60, 0x04, // 2011-2020
0x00, 0x20, 0x60, 0x05, 0x00, // 2021-2030
0x30, 0xb0, 0x06, 0x00, 0x50, // 2031-2040
0x02, 0x07, 0x00, 0x50, 0x03 // 2041-2050
);

// 返回农历iLunarYear年的闰月月份，如没有则返回0
function GetLeapMonth(iLunarYear)
{
var Leap = LunarLeapYear[(iLunarYear - 2001) >> 1];
return (((iLunarYear - 2001) & 1) == 0) ? (Leap >> 4) : (Leap & 0x0f);
}

// 返回农历iLunarYer年iLunarMonth月的天数，结果是一个长整数
// 如果iLunarMonth不是闰月， 高字为0，低字为该月的天数
// 如果iLunarMonth是闰月， 高字为后一个月的天数，低字为前一个月的天数
function LunarMonthDays(iLunarYear, iLunarMonth)
{
var High;
var Low;
var Bit;

High = 0;
Low = 29;
Bit = 16 - iLunarMonth;
if ((iLunarMonth > GetLeapMonth(iLunarYear)) && (GetLeapMonth(iLunarYear) > 0)) Bit--;
if ((LunarDaysOfMonth[iLunarYear - 2001] & (1 << Bit)) > 0) Low++;
if (iLunarMonth == GetLeapMonth(iLunarYear))
{
High = ((LunarDaysOfMonth[iLunarYear - 2001] & (1 << (Bit-1))) > 0) ? 30 : 29;
}

return Low + (High << 16);
}

// 返回农历iLunarYear年的总天数
function LunarYearDays(iLunarYear)
{
var Days;
var tmp;

Days = 0;
for (var i=1; i <= 12; i++)
{
tmp = LunarMonthDays(iLunarYear, i);
Days = Days + ((tmp >> 16) & 0xffff); //取高位
Days = Days + (tmp & 0xffff); //取低位
}

return Days;
}

// 将农历iLunarYear年格式化成天干地支记年法表示的字符串
function FormatLunarYear(iLunarYear)
{
var szText1 = new String("甲乙丙丁戊己庚辛壬癸");
var szText2 = new String("子丑寅卯辰巳午未申酉戌亥");
var strYear;

strYear = szText1.substr((iLunarYear - 4) % 10, 1);
strYear = strYear + szText2.substr((iLunarYear - 4) % 12, 1);

return strYear + "年";
}

// 将农历iLunarMonth月格式化成农历表示的字符串
function FormatLunarMonth(iLunarMonth)
{
var szText = new String("正二三四五六七八九十");
var strMonth;

if (iLunarMonth <= 10)
{
strMonth = szText.substr(iLunarMonth - 1, 1);
}
else if (iLunarMonth == 11) strMonth = "十一";
else strMonth = "十二";

return strMonth + "月";
}

// 将农历iLunarDay日格式化成农历表示的字符串
function FormatLunarDay(iLunarDay)
{
var szText1 = new String("初十廿三");
var szText2 = new String("一二三四五六七八九十");
var strDay;
if ((iLunarDay != 20) && (iLunarDay != 30))
{
strDay = szText1.substr((iLunarDay - 1) / 10, 1) + szText2.substr((iLunarDay - 1) % 10, 1);
}
else if (iLunarDay != 20)
{
strDay = szText1.substr(iLunarDay / 10, 1) + "十";
}
else
{
strDay = "二十";
}

return strDay;
}

// 将公历日期转换为农历日期，返回农历表示的字符串
function GetLunarDateString(SolarDate)
{
var tmp;
var iLunarYear;
var iLunarMonth;
var iLunarDay;
var Leap = false;
var MinMilli = 1000 * 60;
var HrMilli = MinMilli * 60;
var DyMilli = HrMilli * 24;

// 从2001年1月1日算起，给定的公历日期已经过去的天数
// 11323是1970年1月1日到2001年1月1日之间的天数，因为Date是从1970年1月1日作为起点的
var iSpanDays = Math.round(SolarDate.getTime() / DyMilli) - 11323;

// 公历2001年1月24日为农历2001年正月初一，差23天
if (iSpanDays < 23)
{
iYear = 2000;
iLunarMonth = 12;
iLunarDay = iSpanDays + 7;
}
else
{
// 从农历2001年正月初一算起
iSpanDays = iSpanDays - 23;
iLunarYear = 2001;
iLunarMonth = 1;
iLunarDay = 1;

// 计算农历年
tmp = LunarYearDays(iLunarYear);
while (iSpanDays >= tmp)
{
iSpanDays -= tmp;
iLunarYear++;
tmp = LunarYearDays(iLunarYear);
}

// 计算农历月
tmp = LunarMonthDays(iLunarYear, iLunarMonth) & 0xffff; //取低字
while (iSpanDays >= tmp)
{
iSpanDays -= tmp;
if (iLunarMonth == GetLeapMonth(iLunarYear)) // 该年该月闰月
{
tmp = LunarMonthDays(iLunarYear, iLunarMonth) >> 16; //取高字
if (iSpanDays < tmp)
{
Leap = (tmp > 0) ? true : false; // 闰月的后个月？
break;
}
iSpanDays = iSpanDays - tmp;
}

iLunarMonth++;
tmp = LunarMonthDays(iLunarYear,iLunarMonth) & 0xffff; //取低字
}

// 计算农历日
iLunarDay += iSpanDays;
}

return FormatLunarYear(iLunarYear) + "&nbsp;" + (Leap ? "闰" : "") + FormatLunarMonth(iLunarMonth) + FormatLunarDay(iLunarDay);
}

var today= new Date(); // 今天是2004-3-5
var str = GetLunarDateString(today);
document.write("农历"+str);

//调用方法：<script type='text/javascript' src='time.js'></script>