diff --git a/notebooks/wp5/glacier_distribution.ipynb b/notebooks/wp5/glacier_distribution.ipynb
index a37a5b1..5ceb859 100644
--- a/notebooks/wp5/glacier_distribution.ipynb
+++ b/notebooks/wp5/glacier_distribution.ipynb
@@ -130,7 +130,9 @@
     "    date = date.where(~date.str.startswith(\"-\"))\n",
     "    columns.append(pd.to_datetime(date))\n",
     "dates = pd.DataFrame(columns).mean()\n",
-    "gdf[\"decimal_year\"] = dates.year + (dates.dayofyear - 1) / (364 + dates.is_leap_year)\n",
+    "gdf[\"decimal_year\"] = dates.dtyear + (dates.dt.dayofyear - 1) / (\n",
+    "    364 + dates.dt.is_leap_year\n",
+    ")\n",
     "gdf[\"year\"] = dates.dt.year.astype(\"Int64\")"
    ]
   },