/** 判断闰年* @param  {Number} 年* @return {Blooean}*/
function isLeapYear(year) {return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)
}
isLeapYear(2015) // false
isLeapYear(2016) // true

/** 补齐月，日数字位数* @param {number|string} n 需要补齐的数字* @return {string} 补齐两位后的字符*/
function getTwoBit(n) {return (n > 9 ? '' : '0') + n
}
getTwoBit(3)  // '03'
getTwoBit(9)  // '09'
getTwoBit(10) // '10'
getTwoBit(11) // '11'

/** 日期对象转成字符串* @param  {Date} new Date()* @split  {String} "-" 或 "/"* @return {String} "2014-12-31" */
function date2Str(date, split) {split = split || '-'var y = date.getFullYear()var m = getTwoBit(date.getMonth() + 1)var d = getTwoBit(date.getDate())return [y, m, d].join(split)
}

/** 日期字符串转成Date对象* @param {String} str*   "2014-12-31" *   "2014/12/31"* @return {Date} */
function str2Date(str) {var reDate = /^\d{4}\-\d{1,2}\-\d{1,2}/if (reDate.test(str)) {str = str.replace(/-/g, '/')}return new Date(str)
}

/** 返回日期格式字符串* @param {Number} 0返回今天的日期、1返回明天的日期，2返回后天得日期，依次类推* @return {string} '2014-12-31'*/
function getSpecDay(i) {i = i || 0var date = new Datevar diff = i * (1000 * 60 * 60 * 24)date = new Date(date.getTime() + diff)return date2Str(date)
}
getSpecDay(0) // 2014-12-31
getSpecDay(1) // 2015-01-01

/** 根据Date对象获取周几* @param date {Date|String} 如 '2014-12-22'* @param isFormal {Boolean} * @return '周一' 或 '星期一'*/
function getWeekByDate(date, isFormal) {var obj = nullvar weekArr1 = ['周日','周一','周二','周三','周四','周五','周六']var weekArr2 = ['星期日', '星期一','星期二','星期三','星期四','星期五','星期六']if (typeof date == 'string') {obj = str2Date(date)} else if (date instanceof Date) {obj = date}var num = obj.getDay()return isFormal ? weekArr2[num] : weekArr1[num]
}

/** 根据年获取生肖** **参数***  year {number} 年** **示例***  getAnimal(1980) // "猴"*  getAnimal(1981) // "鸡"*  getAnimal(2013) // "蛇"*/
function getAnimal(year) {var animals = ['鼠', '牛', '虎', '兔', '龙', '蛇', '马', '羊', '猴', '鸡', '狗', '猪'];var i = (year - 4) % 12;return animals[i];
}

/** 根据年月返回该月的两个节气，一个公历月有两个节气* * **节气算法***  http://ershisijieqi.baike.com/article-284624.html*  http://www.azg168.com/huangli/24sijieqi/28337.html*  http://blog.csdn.net/orbit/article/details/7910220** **参数***  year  {number} 年 *  month {number} 月** **返回***  object* * **示例***  getSolarTerm(2016, 4); // {day1: 4, term1: "清明", day2: 19, term2: "谷雨"}**/
function getSolarTerm(year, month) {var solarTerm = ["小寒", "大寒", "立春", "雨水", "惊蛰", "春分", "清明", "谷雨", "立夏", "小满", "芒种", "夏至", "小暑", "大暑", "立秋", "处暑", "白露", "秋分", "寒露", "霜降", "立冬", "小雪", "大雪", "冬至"];var termInfo = [0, 21208, 42467, 63836, 85337, 107014, 128867, 150921, 173149, 195551, 218072, 240693, 263343, 285989, 308563, 331033, 353350, 375494, 397447, 419210, 440795, 462224, 483532, 504758];// 返回某年的第n个节气为几日(从0小寒起算)function computeTermDay(y, n) {var d = new Date((31556925974.7 * (y - 1900) + termInfo[n] * 60000) + Date.UTC(1900, 0, 6, 2, 5));return d.getUTCDate();}// month 转为 [0-11] 范畴month = month - 1;// 计算节气var n1 = month * 2;var n2 = month * 2 + 1;// day1, day2 为当月的两个节气日var day1 = computeTermDay(year, n1);var day2 = computeTermDay(year, n2);// 当月的两个节气名称var term1 = solarTerm[n1];var term2 = solarTerm[n2];// 返回结果return {day1: day1,term1: term1,day2: day2,term2: term2};
}

/** 获取Y年的清明节是哪一天*  * **参数***  yare {number} 年** **示例***  getQingMing(2015); // 0405*  getQingMing(2016); // 0404*/
function getQingMing(year) {// [Y*D+C]-L// Y=年数后2位，D=0.2422，L=闰年数，21世纪C=4.81，20世纪=5.59var d = 0.2422;var c = 4.81;var y = (year + '').substr(2);var day = parseInt(y*d+c) - parseInt(y/4);return day;
}