如果数组元素在2个日期之间，则回显文本PHP

我有以下旨在创建HTML电子邮件的PHP代码，该电子邮件应输出所有模型的详细信息，并在2个设置日期之间显示有效日期：

$sql = 'SELECT
GROUP_CONCAT(op.products_model),
GROUP_CONCAT(products.products_warranty_default),
GROUP_CONCAT(orders.date_purchased),
orders.customers_name
FROM orders_products op
INNER JOIN products
    ON op.products_id = products.products_id
INNER JOIN orders
    ON op.orders_id = orders.orders_id
INNER JOIN customers
    ON orders.customers_id = customers.customers_id
GROUP BY op.orders_id';

$result = mysql_query($sql, $connection);

while ($data = mysql_fetch_row($result)) {
    $models = explode(",",$data[0]); // create array from all models in the GROUP_CONCAT
    $years = explode(",",$data[1]); // create array from all years in the GROUP_CONCAT
    $dates = explode(",",$data[2]); // create array from all dates in the GROUP_CONCAT
    $name = $data[3];
    echo $header; // header of email (only the name changes on each loop)
    foreach ($models as $index => $model) {
    echo '
    <tr>
        <td width="149">
            <center>'.$model.'</center>
        </td>
        <td width="149">
            <center>'.date('d/m/Y', strtotime('+'.$years[$index].' years', strtotime($dates[$index]))).'</center>
        </td>
    </tr>'; // echos the model in first column and date+years in second column
    }
    echo $footer; // static HTML again like the header
}

我要坚持的是，如果表中存在一个日期介于2个日期（即2014年5月1日至2014年5月31日）之间的模型，则如何仅输出页眉，表和页脚的组合。它当前正在输出所有日期。

我已经尝试了各种方法来执行此操作，但是在大约6个小时的故障后，我准备将计算机扔到窗外。我只有几周的PHP使用经验（以及与此相关的编程知识），因此（希望）它是我不知道的简单修复方法。

注意：我应该注意，使用当前数据库进行测试时，我可以修改select查询以输出相关日期，但是在使用的实际数据库上（我只能在工作中访问）保修字段，我必须通过php从产品的详细描述中提取信息，并将其提供给函数。

最终代码：

$sql = 'SELECT  op.products_model, 
        products.products_warranty_default,
        orders.date_purchased,
        orders.customers_name
   FROM orders_products op
  INNER JOIN products  ON op.products_id = products.products_id
  INNER JOIN orders    ON op.orders_id = orders.orders_id
  INNER JOIN customers ON orders.customers_id = customers.customers_id
  ORDER BY orders.customers_name, op.orders_id,
           op.products_model,
           products.products_warranty_default,
           orders.date_purchased';
$result = mysql_query($sql, $connection);
$previous_name = "";

while ($data = mysql_fetch_row($result)) {
    $model = $data[0];
    $year = $data[1];
    $date = $data[2];
    $name = $data[3];
    $expiry = strtotime('+'.$year.' years', strtotime($date));
    if ($previous_name != $name && $expiry >= strtotime('2014-05-01') && $expiry <= strtotime('2014-05-31')) {  // on a new customer name ...
        if ($previous_name != "") {
            // if there is a previous customer, write the footer
            echo $footer;
            $previous_name = $name; 
        }
    }
    if ($expiry >= strtotime('2014-05-01') && $expiry <= strtotime('2014-05-31')){
    echo '
    <tr>
        <td width="149">
                <center>'.$model.'</center>
        </td>
        <td width="149">
            <center>'.date('d/m/Y', $expiry).'</center>
        </td>
    </tr>'; // echos the model in first column and date+years in second column
    }
}
if ( $previous_name != "" && $expiry >= strtotime('2014-05-01') && $expiry <= strtotime('2014-05-31')) {
    echo $footer;
}