diff --git a/justfile b/justfile
index 150e1dd..a6fdd52 100644
--- a/justfile
+++ b/justfile
@@ -2,6 +2,8 @@ default: versioned
 
 clean: files kernels unique packages
 
+test:
+
 files:
     python src/files.py input output
 
@@ -15,13 +17,19 @@ packages:
     python src/packages.py input output
 
 versioned:
+    #!/usr/bin/env bash
+    set -euxo pipefail
     datalad get -r "input"
-    datalad run -m "Update dataset" \
+    lastcommit=$(git log -1 --format=%H)
+    date=$(date +%F)
+    datalad run -m "Update dataset for ${date}" \
         -o "input/*.json" -o "output/*.csv" \
         just getraw clean validate
-    printf "\n## %s\n\n- auto generated\n" $(date +%F) | sed -i '/CHANGELOG/r /dev/stdin' CHANGELOG.md
-    git add CHANGELOG.md && git commit -v --no-edit --amend
-    git tag -a "$(date +%F)" -m "Release $(date +%F)"
+    if [ "$lastcommit" != $(git log -1 --format=%H) ]; then
+        printf "\n## %s\n\n- auto generated\n" ${date} | sed -i '/CHANGELOG/r /dev/stdin' CHANGELOG.md
+        git add CHANGELOG.md && git commit -v --no-edit --amend
+        git tag -a "${date}" -m "Release ${date}"
+    fi
 
 # requires python dev dependencies, thus to be running in venv
 validate: