diff --git a/includes/srs_queue.php b/includes/srs_queue.php
new file mode 100644
index 0000000..6dd7c5b
--- /dev/null
+++ b/includes/srs_queue.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+function sortDueWords(array $words): array
+{
+    $today = date('Y-m-d');
+
+    usort($words, function ($a, $b) use ($today) {
+
+        $aDue = $a['nextReview'] ?? '1970-01-01';
+        $bDue = $b['nextReview'] ?? '1970-01-01';
+
+        $aPriority = ($aDue <= $today) ? 0 : 1;
+        $bPriority = ($bDue <= $today) ? 0 : 1;
+
+        if ($aPriority !== $bPriority) {
+            return $aPriority <=> $bPriority;
+        }
+
+        return strcmp($aDue, $bDue);
+    });
+
+    return $words;
+}
\ No newline at end of file