时间/日期 处理

对时间的格式化输出：

 public function DT14($timestamp = null)
 {
    if(empty($timestamp)) $timestamp = time();      
    return strftime("%Y%m%d%H%M%S",$timestamp);
 }
 public function DT19($timestamp  = null)
 {
    if(empty($timestamp)) $timestamp = time();
    return strftime("%Y-%m-%d %H:%M:%S",$timestamp);
 }

获得时间戳：

 public function getmicrotime() 
 { 
    list($usec, $sec) = explode(" ", microtime()); 
    return ((float)$usec + (float)$sec); 
 }