//时间计算 开始，结束，类型
function shijianjisuan($kaishi,$jieshu,$leixing='shi') {
if ($leixing=='shi')//小时
{
$sc = floor((strtotime($jieshu) - strtotime($kaishi)) / 3600);
}
elseif ($leixing=='fen')//分钟
{
$sc = floor((strtotime($jieshu) - strtotime($kaishi)) / 60);
}
elseif ($leixing=='tian')//天
{
$sc = floor((strtotime($jieshu) - strtotime($kaishi)) / 3600/24);
}
return $sc;
}
$a='2016-08-02';
$b='2016-08-04';
echo shijianjisuan($a,$b,'tian');