diff --git a/src/delta_barth/analysis/forecast.py b/src/delta_barth/analysis/forecast.py
index 19ad3d2..90c8dec 100644
--- a/src/delta_barth/analysis/forecast.py
+++ b/src/delta_barth/analysis/forecast.py
@@ -262,8 +262,8 @@ def _process_sales(
     # print("dates: ", dates)
     # ?? --- new: use monthly basis for time windows
     # baseline: 3 years - 36 months
-    starting_date = datetime.datetime.now() - relativedelta(months=12)
-    # starting_date = dates.max() - relativedelta(months=36)
+    # starting_date = datetime.datetime.now() - relativedelta(months=36)
+    starting_date = dates.max() - relativedelta(months=36)
     # start_index = next(
     #     (i for i, date in enumerate(dates) if date >= starting_date), len(dates) - 1
     # )