JS 日期字符串 转换函数

/*将String类型解析为Date类型.      
  parseDate('2006-1-1') return new Date(2006,0,1)      
  parseDate(' 2006-1-1 ') return new Date(2006,0,1)      
  parseDate('2006-1-1 15:14:16') return new Date(2006,0,1,15,14,16)      
  parseDate(' 2006-1-1 15:14:16 ') return new Date(2006,0,1,15,14,16);      
  parseDate('2006-1-1 15:14:16.254') return new Date(2006,0,1,15,14,16,254)      
  parseDate(' 2006-1-1 15:14:16.254 ') return new Date(2006,0,1,15,14,16,254)      
  parseDate('不正确的格式') retrun null      
*/        
function parseDate(str){         
  if(typeof str == 'string'){         
    var results = str.match(/^ *(\d{4})-(\d{1,2})-(\d{1,2}) *$/);         
    if(results && results.length>3)         
      return new Date(parseInt(results[1]),parseInt(results[2]) -1,parseInt(results[3]));          
    results = str.match(/^ *(\d{4})-(\d{1,2})-(\d{1,2}) +(\d{1,2}):(\d{1,2}):(\d{1,2}) *$/);         
    if(results && results.length>6)         
     return new Date(parseInt(results[1]),parseInt(results[2]) -1,parseInt(results[3]),parseInt(results[4]),parseInt(results[5]),parseInt(results[6]));          
    results = str.match(/^ *(\d{4})-(\d{1,2})-(\d{1,2}) +(\d{1,2}):(\d{1,2}):(\d{1,2})\.(\d{1,9}) *$/);         
    if(results && results.length>7)         
      return new Date(parseInt(results[1]),parseInt(results[2]) -1,parseInt(results[3]),parseInt(results[4]),parseInt(results[5]),parseInt(results[6]),parseInt(results[7]));          
  }         
  return null;         
}         
  
/*      
  将Date/String类型,解析为String类型.      
  传入String类型,则先解析为Date类型      
  不正确的Date,返回 ''      
  如果时间部分为0,则忽略,只返回日期部分.      
*/        
function formatDate(v){         
  if(typeof v == 'string') v = parseDate(v);         
  if(v instanceof Date){         
    var y = v.getFullYear();         
    var m = v.getMonth() + 1;         
    var d = v.getDate();         
    var h = v.getHours();         
    var i = v.getMinutes();         
    var s = v.getSeconds();         
    var ms = v.getMilliseconds();            
    if(ms>0) return y + '-' + m + '-' + d + ' ' + h + ':' + i + ':' + s + '.' + ms;         
    if(h>0 || i>0 || s>0) return y + '-' + m + '-' + d + ' ' + h + ':' + i + ':' + s;         
    return y + '-' + m + '-' + d;         
  }         
  return '';         
}