diff --git a/anki_helpers/activity.py b/anki_helpers/activity.py
index e69de29bb..c2226f9d7 100644
--- a/anki_helpers/activity.py
+++ b/anki_helpers/activity.py
@@ -0,0 +1,30 @@
+import time
+from collections import defaultdict
+
+def analyze_activity(col, days=30):
+    day_cutoff = col.sched.day_cutoff
+    start_time = day_cutoff - days * 86400
+    start_ts = start_time * 1000  # ms
+
+    rows = col.db.all(
+        """
+        SELECT id FROM revlog
+        WHERE id > ?
+        """,
+        start_ts,
+    )
+
+    days_dict = defaultdict(int)
+    for (id,) in rows:
+        day = int((id / 1000) // 86400)
+        days_dict[day] += 1
+
+    total_days = len(days_dict)
+    average_per_day = sum(days_dict.values()) / days
+    low_days = sum(1 for v in days_dict.values() if v < 10)  # z. B. Schwelle
+
+    return {
+        "active_days": total_days,
+        "average_per_day": round(average_per_day, 2),
+        "low_days": low_days,
+    }