diff --git a/src/uim/explouim.py b/src/uim/explouim.py
index 95450cd5b4fa6adcf4e5af31e7071b6c75286bf1..1d493a947e50b7e03ad6aa76ba8bb8f08996c966 100644
--- a/src/uim/explouim.py
+++ b/src/uim/explouim.py
@@ -708,7 +708,7 @@ class ExploUim:
             return
 
         # Convert epoch timestamps to ISO datetime strings
-        boundaries_list = [datetime.datetime.fromtimestamp(boundary).strftime(utils.datetime_format)
+        boundaries_list = [datetime.datetime.fromtimestamp(boundary, tz=datetime.timezone.utc).strftime(utils.datetime_format)
                            for boundary in boundaries_list]
 
         self.stab_window.ui.stab_lineedit_timeranges.setText("\t".join(boundaries_list))