php 计算距离天的时间还有多少天

$syday = 0;
$month = (date("m-d",$value['ctime']));
$year = (date("Y",time()));
$end_date = (date("Y",time()))."-".$month;
if(time()>$value['ctime']) //计算明年的时间差
{
$end_date = ($year+1)."-".$month;
$syday=ceil((strtotime($end_date)-time())/86400); //60s*60min*24h
}else{
$end_date = ($year)."-".$month;
$syday=ceil((time()-strtotime($end_date))/86400); //60s*60min*24h
}