DateUtils = {
  patterns: {
   PATTERN_ERA: 'G', //Era 标志符 Era strings. For example: "AD" and "BC"
   PATTERN_YEAR: 'y', //年
   PATTERN_MONTH: 'M', //月份
   PATTERN_DAY_OF_MONTH: 'd', //月份的天数
   PATTERN_HOUR_OF_DAY1: 'k', //一天中的小时数（1-24）
   PATTERN_HOUR_OF_DAY0: 'H', //24小时制，一天中的小时数（0-23）
   PATTERN_MINUTE: 'm', //小时中的分钟数
   PATTERN_SECOND: 's', //秒
   PATTERN_MILLISECOND: 'S', //毫秒
   PATTERN_DAY_OF_WEEK: 'E', //一周中对应的星期，如星期一，周一
   PATTERN_DAY_OF_YEAR: 'D', //一年中的第几天
   PATTERN_DAY_OF_WEEK_IN_MONTH: 'F', //一月中的第几个星期(会把这个月总共过的天数除以7,不够准确，推荐用W)
   PATTERN_WEEK_OF_YEAR: 'w', //一年中的第几个星期
   PATTERN_WEEK_OF_MONTH: 'W', //一月中的第几星期(会根据实际情况来算)
   PATTERN_AM_PM: 'a', //上下午标识
   PATTERN_HOUR1: 'h', //12小时制 ，am/pm 中的小时数（1-12）
   PATTERN_HOUR0: 'K', //和h类型
   PATTERN_ZONE_NAME: 'z', //时区名
   PATTERN_ZONE_VALUE: 'Z', //时区值
   PATTERN_WEEK_YEAR: 'Y', //和y类型
   PATTERN_ISO_DAY_OF_WEEK: 'u',
   PATTERN_ISO_ZONE: 'X'
  },
  week: {
   'ch': {
    "0": "\u65e5",
    "1": "\u4e00",
    "2": "\u4e8c",
    "3": "\u4e09",
    "4": "\u56db",
    "5": "\u4e94",
    "6": "\u516d"
   },
   'en': {
    "0": "Sunday",
    "1": "Monday",
    "2": "Tuesday",
    "3": "Wednesday",
    "4": "Thursday",
    "5": "Friday",
    "6": "Saturday"
   }
  },
  //获取当前时间
  getCurrentTime: function() {
   var today = new Date();
   var year = today.getFullYear();
   var month = today.getMonth() + 1;
   var day = today.getDate();
   var hours = today.getHours();
   var minutes = today.getMinutes();
   var seconds = today.getSeconds();
   var timeString = year + "-" + month + "-" + day + " " + hours + ":" + minutes + ":" + seconds;
   return timeString;
  },
  /*
   * 比较时间大小
   * time1>time2 return 1
   * time1<time2 return -1
   * time1==time2 return 0
   */
  compareTime: function(time1, time2) {
   if(Date.parse(time1.replace(/-/g, "/")) > Date.parse(time2.replace(/-/g, "/"))) {
    return 1;
   } else if(Date.parse(time1.replace(/-/g, "/")) < Date.parse(time2.replace(/-/g, "/"))) {
    return -1;
   } else if(Date.parse(time1.replace(/-/g, "/")) == Date.parse(time2.replace(/-/g, "/"))) {
    return 0;
   }
  },
  //是否闰年
  isLeapYear: function(year) {
   return((year % 4 === 0 && year % 100 !== 0) || year % 400 === 0);
  },
  //获取某个月的天数，从0开始
  getDaysOfMonth: function(year, month) {
   return [31, (this.isLeapYear(year) "-" + (today.getMonth() + 1) + "-" + today.getDate();
   return date;
  },
  /**
   * 日期时间格式化
   * @param {Object} dateTime 需要格式化的日期时间
   * @param {String} pattern 格式化的模式，如yyyy-MM-dd hh(HH):mm:ss.S a k K E D F w W z Z
   */
  formt: function(dateTime, pattern) {
   var date = new Date(dateTime);
   if(Bee.StringUtils.isBlank(pattern)) {
    return date.toLocaleString();
   }
   return pattern.replace(/([a-z])\1*/ig, function(matchStr, group1) {
    var replacement = "";
    switch(group1) {
     case Bee.DateUtils.patterns.PATTERN_ERA: //G
      break;
     case Bee.DateUtils.patterns.PATTERN_WEEK_YEAR: //Y
     case Bee.DateUtils.patterns.PATTERN_YEAR: //y
      replacement = date.getFullYear();
      break;
     case Bee.DateUtils.patterns.PATTERN_MONTH: //M
      var month = date.getMonth() + 1;
      replacement = (month < 10 && matchStr.length >= 2) "0" + month : month;
      break;
     case Bee.DateUtils.patterns.PATTERN_DAY_OF_MONTH: //d
      var days = date.getDate();
      replacement = (days < 10 && matchStr.length >= 2) "0" + days : days;
      break;
     case Bee.DateUtils.patterns.PATTERN_HOUR_OF_DAY1: //k(1~24)
      var hours24 = date.getHours();
      replacement = hours24;
      break;
     case Bee.DateUtils.patterns.PATTERN_HOUR_OF_DAY0: //H(0~23)
      var hours24 = date.getHours();
      replacement = (hours24 < 10 && matchStr.length >= 2) "0" + hours24 : hours24;
      break;
     case Bee.DateUtils.patterns.PATTERN_MINUTE: //m
      var minutes = date.getMinutes();
      replacement = (minutes < 10 && matchStr.length >= 2) "0" + minutes : minutes;
      break;
     case Bee.DateUtils.patterns.PATTERN_SECOND: //s
      var seconds = date.getSeconds();
      replacement = (seconds < 10 && matchStr.length >= 2) "0" + seconds : seconds;
      break;
     case Bee.DateUtils.patterns.PATTERN_MILLISECOND: //S
      var milliSeconds = date.getMilliseconds();
      replacement = milliSeconds;
      break;
     case Bee.DateUtils.patterns.PATTERN_DAY_OF_WEEK: //E
      var day = date.getDay();
      replacement = Bee.DateUtils.week['ch'][day];
      break;
     case Bee.DateUtils.patterns.PATTERN_DAY_OF_YEAR: //D
      replacement = Bee.DateUtils.dayOfTheYear(date);
      break;
     case Bee.DateUtils.patterns.PATTERN_DAY_OF_WEEK_IN_MONTH: //F
      var days = date.getDate();
      replacement = Math.floor(days / 7);
      break;
     case Bee.DateUtils.patterns.PATTERN_WEEK_OF_YEAR: //w
      var days = Bee.DateUtils.dayOfTheYear(date);
      replacement = Math.ceil(days / 7);
      break;
     case Bee.DateUtils.patterns.PATTERN_WEEK_OF_MONTH: //W
      var days = date.getDate();
      replacement = Math.ceil(days / 7);
      break;
     case Bee.DateUtils.patterns.PATTERN_AM_PM: //a
      var hours24 = date.getHours();
      replacement = hours24 < 12 "\u4e0a\u5348" : "\u4e0b\u5348";
      break;
     case Bee.DateUtils.patterns.PATTERN_HOUR1: //h(1~12)
      var hours12 = date.getHours() % 12 || 12; //0转为12
      replacement = (hours12 < 10 && matchStr.length >= 2) "0" + hours12 : hours12;
      break;
     case Bee.DateUtils.patterns.PATTERN_HOUR0: //K(0~11)
      var hours12 = date.getHours() % 12;
      replacement = hours12;
      break;
     case Bee.DateUtils.patterns.PATTERN_ZONE_NAME: //z
      replacement = Bee.DateUtils.getZoneNameValue(date)['name'];
      break;
     case Bee.DateUtils.patterns.PATTERN_ZONE_VALUE: //Z
      replacement = Bee.DateUtils.getZoneNameValue(date)['value'];
      break;
     case Bee.DateUtils.patterns.PATTERN_ISO_DAY_OF_WEEK: //u
      break;
     case Bee.DateUtils.patterns.PATTERN_ISO_ZONE: //X
      break;
     default:
      break;
    }
    return replacement;
   });
  },
  /**
   * 计算一个日期是当年的第几天
   * @param {Object} date
   */
  dayOfTheYear: function(date) {
   var obj = new Date(date);
   var year = obj.getFullYear();
   var month = obj.getMonth(); //从0开始
   var days = obj.getDate();
   var daysArr = [31, (this.isLeapYear(year) "color: #ff6600">在线HTML/CSS/JavaScript代码运行工具：http://tools.jb51.net/code/HtmlJsRun测试运行结果如下：


PS：这里再为大家推荐几款比较实用的天数计算在线工具供大家使用：
在线日期/天数计算器：

http://tools.jb51.net/jisuanqi/date_jisuanqi
在线日期计算器/相差天数计算器：

http://tools.jb51.net/jisuanqi/datecalc
在线日期天数差计算器：

http://tools.jb51.net/jisuanqi/onlinedatejsq
在线天数计算器：

http://tools.jb51.net/jisuanqi/datejsq
更多关于JavaScript相关内容感兴趣的读者可查看本站专题：《JavaScript时间与日期操作技巧总结》、《JavaScript+HTML5特效与技巧汇总》、《JavaScript错误与调试技巧总结》、《JavaScript数据结构与算法技巧总结》及《JavaScript数学运算用法总结》
希望本文所述对大家JavaScript程序设计有所帮助。