JavaScript 日期格式化

  DateFormat = {  
   format : function(date,formatter){  
    if(date==null){return null;};  
    if(formatter==null){formatter = "yyyy-MM-dd";};  
    var year = date.getYear().toString();  
    var month = (date.getMonth() + 1).toString();  
    var day = date.getDate().toString();  
    var hours = date.getHours().toString();  
    var minutes = date.getMinutes().toString();  
    var seconds = date.getSeconds().toString();  
    var yearMarker = formatter.replace(/[^y]/g,'');  
    var monthMarker = formatter.replace(/[^M]/g,'');  
    var dayMarker = formatter.replace(/[^d]/g,'');  
    var hoursMarker = formatter.replace(/[^h]/g,'');  
    var minutesMarker = formatter.replace(/[^m]/g,'');  
    var secondsMarker = formatter.replace(/[^s]/g,'');  
    if(yearMarker.length == 2){year = year.substring(2,4);};  
    if(monthMarker.length > 1 && month.length==1){month = "0" + month;};  
    if(dayMarker.length > 1 && day.length==1){day = "0" + day;};  
    if(hoursMarker.length > 1 && hours.length==1){hours = "0" + hours;};  
    if(minutesMarker.length > 1 && minutes.length==1){minutes = "0" + minutes;};  
    if(secondsMarker.length > 1 && seconds.length==1){seconds = "0" + seconds;};  
     if(yearMarker.length>0){formatter = formatter.replace(yearMarker,year);}  
     if(monthMarker.length>0){formatter = formatter.replace(monthMarker,month);};  
     if(dayMarker.length>0){formatter = formatter.replace(dayMarker,day);};  
    if(hoursMarker.length>0){formatter = formatter.replace(hoursMarker,hours);};  
     if(minutesMarker.length>0){formatter = formatter.replace(minutesMarker,minutes);};     
     if(secondsMarker.length>0){formatter = formatter.replace(secondsMarker,seconds);};  
     return formatter;  
    },  
    parse : function(dateString,formatter){  
     var today = new Date();  
     if(dateString==null){return today;};  
     if(formatter==null){formatter = "yyyy-MM-dd";};  
     var yearMarker = formatter.replace(/[^y]/g,'');  
     var monthMarker = formatter.replace(/[^M]/g,'');  
     var dayMarker = formatter.replace(/[^d]/g,'');  
     var hoursMarker = formatter.replace(/[^h]/g,'');  
     var minutesMarker = formatter.replace(/[^m]/g,'');  
     var secondsMarker = formatter.replace(/[^s]/g,'');  
     var yearPosition = formatter.indexOf(yearMarker);  
     var yearLength = yearMarker.length;  
     var year = parseInt( dateString.substring(yearPosition ,yearPosition + yearLength) );  
     if(isNaN(year)){  
      year = today.getYear();  
     }else{  
      if( yearLength == 2){  
       if(year < 50 ){  
        year += 2000;  
       }else{  
        year += 1900;  
       };  
      };  
     };  
     var monthPosition = formatter.indexOf(monthMarker);  
     var month = parseInt( dateString.substring(monthPosition,monthPosition + monthMarker.length) );  
     if(isNaN(month)){  
      month = today.getMonth();  
     }else{  
      month-=1  
     };  
     var dayPosition = formatter.indexOf(dayMarker);  
     var day = parseInt( dateString.substring( dayPosition,dayPosition + dayMarker.length ) );  
    if(isNaN(day)){  
     day = today.getDate();  
    }else{  
    };  
    var hoursPosition = formatter.indexOf(hoursMarker);  
    var hours = parseInt( dateString.substring( hoursPosition,hoursPosition + hoursMarker.length ) );  
     if(isNaN(hours)){  
      hours = 0;  
     };  
     var minutesPosition = formatter.indexOf(minutesMarker);  
     var minutes = parseInt( dateString.substring( minutesPosition,minutesPosition + minutesMarker.length ) );  
    if(isNaN(minutes)){  
     minutes = 0;  
    };  
    var secondsPosition = formatter.indexOf(secondsMarker);  
    var seconds = parseInt( dateString.substring( secondsPosition,secondsPosition + secondsMarker.length ) );  
     if(isNaN(seconds)){  
      seconds = 0;  
     };  
     return new Date(year,month,day, hours,minutes,seconds);  
    }  
   };  

//将一个 Date 格式化为日期/时间字符串。
alert(  DateFormat.format(new Date(),'yyyy年MM月dd日')  );
//从给定字符串的开始分析文本，以生成一个日期。
alert(  DateFormat.parse('20100317','yyyyMMdd')  );