here

<?php
/**
 * Let administrators add or remove premium days from themselves or other users.
 */

// Not an admin? Go away!
if (!IsModerator())
{
    header("Location: index.php");
    return;
}
TableHeader("Select person you want to Add or remove Premium Days too then click Add or Remove");
// An Premium Days has been defined
if (isset($_POST['user']))
{
    $user = FindUser($_POST['user']);
    // User not found
    if ($user == NULL)
        ErrorMessage("User not found.");
    else if (is_integer($_POST['quantity']))
        ResultMessage("Must be a number");
    else if ($_POST['quantity'] + 0 > 1000)
        ResultMessage("Must be between 0 and 1000 days.");
    else if ($_POST['quantity'] + 0 < 0)
        ResultMessage("Must be between 0 and 1000 days");
    else
    {
        // Let's try to add the Premium Days.
        try
        {
            if (isset($_POST["cmd"]))
            {
                $name = $db->LoadData("select username from users where id = ?", $_POST["user"]);
                $currentMembership = GetUserVariable(premiumMember, $_POST["user"]);
                $start = date("y-m-d",time());
                $end = strtotime(date("y-m-d",GetUserVariable(premiumMember, $_POST["user"])));
                $days_between = dateDiff($start,$end,3);
                if ($_POST["cmd"] == "add")
                {
                    $result = $db->Execute("select username from users where id =?", $user);
                    if ($currentMembership == null || $currentMembership + 0 < time())
                        $currentMembership = time() + ($_POST["quantity"] * 60 * 60 * 24);
                    else
                        $currentMembership += $_POST["quantity"] * 60 * 60 * 24;
                    SetUserVariable(premiumMember, $currentMembership, $_POST["user"]);
                    ResultMessage(Translate("%s Days were given to User: %s", $_POST["quantity"], $name["username"]));
                    $timeL = floor(time() - GetUserVariable(premiumMember, $_POST["user"]) % 60 / 86400);
                    if (function_exists("SendMessage"))
                        SendMessage($_POST["user"], "You got a gift", Translate("We have decided to give you %s Premium Days, your status ends in %s. Enjoy them", $_POST["quantity"],$days_between), 1);
                }
                else if ($_POST["cmd"] == "remove")
                {
                    $date = GetUserVariable(premiumMember, $_POST["user"]) - time();
                    $result = $db->Execute("select username from users where id =?", $user);
                    $currentMembership = GetUserVariable(premiumMember, $_POST["user"]);
                    if ($currentMembership == null || $currentMembership + 0 < time())
                        $currentMembership = time() + ($_POST["quantity"] * 60 * 60 * 24);
                    else
                        $currentMembership -= $_POST["quantity"] * 60 * 60 * 24;
                    SetUserVariable(premiumMember, $currentMembership, $_POST["user"]);
                    ResultMessage(Translate("%s Days were removed from User: %s", $_POST["quantity"], $name["username"]));
                    if (function_exists("SendMessage"))
                        SendMessage($_POST["user"], "I have bad news", Translate("You have lost %s Premium Days. If you have any question contact staff", $_POST["quantity"]), 1);
                }
                else
                {
                    ResultMessage(Translate("All Premium Days were removed from User: %s", $name["username"]));
                    if (function_exists("SendMessage"))
                        SendMessage($_POST["user"], "I have bad news", Translate("You have lost your Premium status. If you have any question contact staff"), 1);
                    SetUserVariable(premiumMember, time(), $_POST["user"]);
                }

            }
        }
        catch (Exception $ex)
        {
            ErrorMessage($ex->getMessage());
        }
    }
}

if (!isset($_POST['user']))
    $_POST['user'] = $userId;
if (!isset($_POST['quantity']))
    $_POST['quantity'] = 1;
echo "<form method='post' name='frmPremium'>";
echo "<table class='plainTable'>";
echo "<input type='hidden' name='cmd' value='add'>";

echo "<tr><td width='1%'>" . Translate("User:") . "</td><td>" . SmartSelection("select id,username from users where id <> 1", "user", $_POST['user']) . "</td></tr>";
echo "<tr><td width='1%'>" . Translate("Days:") . "</td><td><input type='text' name='quantity' value='" . htmlentities($_POST['quantity']) . "'></td></tr>";
echo "</table>";
echo "</form>";

ButtonArea();
SubmitButton("Add", "frmPremium");
LinkButton("Remove", "#", "document.forms['frmPremium'].cmd.value='remove';document.forms['frmPremium'].submit();return false;");
LinkButton("Remove Status", "#", "document.forms['frmPremium'].cmd.value='drop';document.forms['frmPremium'].submit();return false;");
EndButtonArea();

//Special Thanks to http://www.if-not-true-then-false.com/2010/php-calculate-real-differences-between-two-dates-or-timestamps

function dateDiff($time1, $time2, $precision = 6) {
    // If not numeric then convert texts to unix timestamps
    if (!is_int($time1)) {
      $time1 = strtotime($time1);
    }
    if (!is_int($time2)) {
      $time2 = strtotime($time2);
    }

    // If time1 is bigger than time2
    // Then swap time1 and time2
    if ($time1 > $time2) {
      $ttime = $time1;
      $time1 = $time2;
      $time2 = $ttime;
    }

    // Set up intervals and diffs arrays
    $intervals = array('year','month','day','hour','minute','second');
    $diffs = array();

    // Loop thru all intervals
    foreach ($intervals as $interval) {
      // Set default diff to 0
      $diffs[$interval] = 0;
      // Create temp time from time1 and interval
      $ttime = strtotime("+1 " . $interval, $time1);
      // Loop until temp time is smaller than time2
      while ($time2 >= $ttime) {
    $time1 = $ttime;
    $diffs[$interval]++;
    // Create new temp time from time1 and interval
    $ttime = strtotime("+1 " . $interval, $time1);
      }
    }

    $count = 0;
    $times = array();
    // Loop thru all diffs
    foreach ($diffs as $interval => $value) {
      // Break if we have needed precission
      if ($count >= $precision) {
    break;
      }
      // Add value and interval
      // if value is bigger than 0
      if ($value > 0) {
    // Add s if value is not 1
    if ($value != 1) {
      $interval .= "s";
    }
    // Add value and interval to times array
    $times[] = $value . " " . $interval;
    $count++;
      }
    }

    // Return string with times
    return implode(", ", $times);
  }