diff --git a/src/post_processing/utils/filtering_utils.py b/src/post_processing/utils/filtering_utils.py
index a965e41..db1484f 100644
--- a/src/post_processing/utils/filtering_utils.py
+++ b/src/post_processing/utils/filtering_utils.py
@@ -181,7 +181,7 @@ def get_timezone(df: DataFrame) -> tzoffset | list[tzoffset]:
     timezones = {ts.tz for ts in df["start_datetime"] if ts.tz is not None}
     if len(timezones) == 1:
         return next(iter(timezones))
-    return sorted(timezones, key=lambda tz: tz.utcoffset(None))
+    return list(timezones)
 
 
 def reshape_timebin(
diff --git a/src/post_processing/utils/plot_utils.py b/src/post_processing/utils/plot_utils.py
index 9641f73..9fdcefb 100644
--- a/src/post_processing/utils/plot_utils.py
+++ b/src/post_processing/utils/plot_utils.py
@@ -199,6 +199,9 @@ def _prepare_timeline_plot(
 
     if show_rise_set:
         tz = get_timezone(df)
+        if isinstance(tz, list):
+            msg = "Several timezones not supported."
+            raise ValueError(msg)
         add_sunrise_sunset(ax, lat, lon, tz)