YII2 get the date after 10 years and 5 years - mysql

Question

Here is the table structure.
tbl_staff
firstname varchar(50)
midname varchar(50)
lastname varchar(50)
...
tbl_staff2
first_day_of_service date
...
Here is the scenario.
For the first 10 years of stay of the staff in organization, he/she will be given a loyalty award and then every 5 years after he/she receives the first 10 years.
My initial code will just get the name of staff and the date of first day of service.
public function actionGet_loyalty() {
$query = (new \yii\db\Query())
->select(['firstname', 'midname', 'lastname', 'first_day_service'])
->from('tbl_staff')
->limit(100)
->offset(0)
->orderBy('first_day_service')
->leftJoin('tbl_staff2', 'tbl_staff2.staff_id = tbl_staff.id');
$command = $query->createCommand();
$data = $command->queryAll();
$string = "<table class='table table-striped'><tr><th>No.</th><th>Name</th><th>Date to Receive Loyalty Award</th></tr>";
$i = 1;
foreach ($data as $row) {
$firstname = $row['firstname'];
$midname = $row['midname'];
$lastname = $row['lastname'];
//$string.=$row['first_day_service'];
$string.="<tr>"
. "<td>$i</td>"
. "<td>" . $firstname . " " . $midname[0] . ". " . $lastname . "</td>"
. "<td>" . $row['first_day_service'] . "</td>"
. "</tr>";
$i++;
}
$string.="</table>";
return $string;
}
How to display all the name of staff and the date he/she will receive the award in increasing order.
Or any mysql query that will sort the name according the date?

Answer 1

If you want to do it via SQL query, in MySQL you can add date using DATE_ADD function:
DATE_ADD(date, INTERVAL 5 YEAR)
Check this similar question.
Or via PHP using DateTime modify method:
$dateTime = new DateTime($date);
$dateTime->modify('+ 5 years')->format('Y-m-d H:i:s');