diff --git a/scripts/autoload/flashcard_service.gd b/scripts/autoload/flashcard_service.gd
index ad78fb6..7497090 100644
--- a/scripts/autoload/flashcard_service.gd
+++ b/scripts/autoload/flashcard_service.gd
@@ -90,7 +90,7 @@ func current_study_day_start_utc() -> String:
 		"hour": 0, "minute": 0, "second": 0
 	})
 	var utc_unix: int = local_midnight_unix + utc_offset_minutes * 60
-	return "%sZ" % Time.get_datetime_string_from_unix_time(utc_unix, true)
+	return "%sZ" % Time.get_datetime_string_from_unix_time(utc_unix, false)
 
 
 # ---------- Next card / study session ----------