diff --git a/Lab 1 - Group Work/rename.sh b/Lab 1 - Group Work/rename.sh
new file mode 100644
index 0000000..279d2c7
--- /dev/null
+++ b/Lab 1 - Group Work/rename.sh	
@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="${1:-lab1_files/file_renaming/reorganized}"
+
+export LC_TIME=C
+TODAY="$(date +'%d%b%Y')" 
+
+make_filename() {
+  local chapter="$1"
+  local dataset="$2"
+  echo "CH${chapter}_DS${dataset}_${TODAY}.sav"
+}
+
+shopt -s nullglob
+
+for chapter_dir in "$ROOT_DIR"/Chapter*; do
+  [[ -d "$chapter_dir" ]] || continue
+
+  chapter_num="${chapter_dir##*/Chapter}"
+
+  for file in "$chapter_dir"/DataSet*.sav; do
+    base="$(basename "$file")"
+
+    dataset_num="$(echo "$base" | sed -E 's/^DataSet([0-9]+)\.sav$/\1/')"
+    [[ "$dataset_num" =~ ^[0-9]+$ ]] || continue
+
+    new_name="$(make_filename "$chapter_num" "$dataset_num")"
+    mv -f "$file" "$chapter_dir/$new_name"
+  done
+done
+
+echo "Rename complete."