$start=new DateTime('2017-02-20');  
$end=new DateTime('2017-03-10');  
foreach(new DatePeriod($start,new DateInterval('P1D'),$end) as $d){  
    /** 
     * @var $d DateTime 
     */  
    echo $d->format('Y-m-d')."\r\n";  
}

输出

2017-02-20  
2017-02-21  
2017-02-22  
2017-02-23  
2017-02-24  
2017-02-25  
2017-02-26  
2017-02-27  
2017-02-28  
2017-03-01  
2017-03-02  
2017-03-03  
2017-03-04  
2017-03-05  
2017-03-06  
2017-03-07  
2017-03-08  
2017-03-09