Fix flaky tests - date handling in generate_different_date_within_collection_year

app/helpers/collection_time_helper.rb

@@ -55,8 +55,8 @@ module CollectionTimeHelper
   end
 
   def generate_different_date_within_collection_year(date, start_date_override: nil, end_date_override: nil)
-    start_date = [start_date_override, collection_start_date(date).to_date].compact.max.to_date
-    end_date = [end_date_override, collection_end_date(date).to_date].compact.min.to_date
+    start_date = [start_date_override&.to_date, collection_start_date(date).to_date].compact.max.to_date
+    end_date = [end_date_override&.to_date, collection_end_date(date).to_date].compact.min.to_date
 
     return nil if start_date >= end_date