问PHP日期计算器返回错误的日期

EN

function relationshipTimer($functionDate)
{
    $date1 = $functionDate;
    $date2 = date("Y-m-d");
    $diff = abs(strtotime($date2) - strtotime($date1));
    $years = floor($diff / (365 * 60 * 60 * 24));
    $months = floor(($diff - ($years * 365 * 60 * 60 * 24)) / ((365 * 60 * 60 * 24) / 12));
    $days = floor(($diff - $years * 365 * 60 * 60 * 24 - $months * 30 * 60 * 60 * 24) / (60 * 60 * 24));
    if ($years > 0) {echo $years . " Year";}
    if ($years > 1) {echo "s ";}
    if ($months > 0) {echo " " . $months . " Month";}
    if ($months > 1) {echo "s ";}
    if ($date1 == $date2) {echo "1 Day ";}
    if ($days > 0) {echo $days . " Day";}
    if ($days > 1) {echo "s ";}
}