在.net2.0 的版本中的 System.Globalization.ChineseLunisolarCalendar 是针对中国的日历类，公历与中国传统农历纪年之间的相互转换，利用它可以计算天干地支等有关农历的信息。

使用

static ChineseLunisolarCalendar cCalendar = new ChineseLunisolarCalendar();

cCalendar.MaxSupportedDateTime 返回支持的最大日期，即2101-1-28

cCalendar.MinSupportedDateTime  返回支持的最小日期，即1901－2-19

下面我们来实现公历转农历。

/// <summary>
/// 根据公历获取农历日期
/// </summary>
/// <param name="datetime">公历日期</param>
/// <returns></returns>
public static string GetChineseDateTime(DateTime datetime)
{int lyear = cCalendar.GetYear(datetime);int lmonth = cCalendar.GetMonth(datetime);int lday = cCalendar.GetDayOfMonth(datetime);//获取闰月， 0 则表示没有闰月int leapMonth = cCalendar.GetLeapMonth(lyear);bool isleap = false;if (leapMonth > 0){if (leapMonth == lmonth){//闰月isleap = true;lmonth--;}else if (lmonth > leapMonth){lmonth--;}}return string.Concat(GetLunisolarYear(lyear), "年", isleap ? "闰" : string.Empty, GetLunisolarMonth(lmonth), "月", GetLunisolarDay(lday));}

测试的结果:

传入日期：2010-3-4

返回农历：庚寅[虎]年正月十九

可以满足简单的需求啦。

其他代码也附上：

#region 农历年/// <summary>
/// 十天干
/// </summary>
private static string[] tiangan = { "甲", "乙", "丙", "丁", "戊", "己", "庚", "辛", "壬", "癸" };/// <summary>
/// 十二地支
/// </summary>
private static string[] dizhi = { "子", "丑", "寅", "卯", "辰", "巳", "午", "未", "申", "酉", "戌", "亥" };/// <summary>
/// 十二生肖
/// </summary>
private static string[] shengxiao = { "鼠", "牛", "虎", "免", "龙", "蛇", "马", "羊", "猴", "鸡", "狗", "猪" };/// <summary>
/// 返回农历天干地支年
/// </summary>
/// <param name="year">农历年</param>
/// <returns></returns>
public static string GetLunisolarYear(int year)
{if (year > 3){int tgIndex = (year - 4) % 10;int dzIndex = (year - 4) % 12;return string.Concat(tiangan[tgIndex], dizhi[dzIndex], "[", shengxiao[dzIndex], "]");}throw new ArgumentOutOfRangeException("无效的年份!");
}       #endregion

#region 农历月/// <summary>
/// 农历月
/// </summary>
private static string[] months = { "正", "二", "三", "四", "五", "六", "七", "八", "九", "十", "十一", "十二(腊)" };/// <summary>
/// 返回农历月
/// </summary>
/// <param name="month">月份</param>
/// <returns></returns>
public static string GetLunisolarMonth(int month)
{if (month < 13 && month > 0){return months[month - 1];}throw new ArgumentOutOfRangeException("无效的月份!");
}#endregion

#region 农历日/// <summary>
///
/// </summary>
private static string[] days1 = { "初", "十", "廿", "三" };/// <summary>
/// 日
/// </summary>
private static string[] days = { "一", "二", "三", "四", "五", "六", "七", "八", "九", "十" };/// <summary>
/// 返回农历日
/// </summary>
/// <param name="day"></param>
/// <returns></returns>
public static string GetLunisolarDay(int day)
{if (day > 0 && day < 32){if (day != 20 && day != 30){return string.Concat(days1[(day - 1) / 10], days[(day - 1) % 10]);}else{return string.Concat(days[(day - 1) / 10], days1[1]);}}throw new ArgumentOutOfRangeException("无效的日!");
}#endregion

还有一个根据日期获取生肖的代码:

/// <summary>
/// 返回生肖
/// </summary>
/// <param name="datetime">公历日期</param>
/// <returns></returns>
public static string GetShengXiao(DateTime datetime)
{return shengxiao[cCalendar.GetTerrestrialBranch(cCalendar.GetSexagenaryYear(datetime)) - 1];
}

一切都变的简单了。