upload.php

<?php
$dir = '/reports';
$key_name = 'file';
$key_imei = 'imei';

if(isset($_FILES[$key_name]) && !is_null($file = $_FILES[$key_name]) && !is_null($imei = $_POST[$key_imei])) {
	$now = new \DateTime('NOW');
	$date_dir = sprintf("%s/%s/%s", $now->format('Y'),$now->format('m'),$now->format('d'));

	$full_path_dir = sprintf("%s/%s/%s",getcwd(), $dir, $date_dir);

	if(!file_exists($full_path_dir)) {
		mkdir($full_path_dir, 0777, true);
	}

  $file_name = sprintf("%s_%s.zip", $imei, $now->getTimeStamp());

  $full_path_file = $full_path_dir.'/'. $file_name;

	move_uploaded_file($file['tmp_name'], $full_path_file);
}