diff --git a/src/calibre/gui2/dialogs/metadata_bulk.py b/src/calibre/gui2/dialogs/metadata_bulk.py
index eb44ec3123..84bf7f6f57 100644
--- a/src/calibre/gui2/dialogs/metadata_bulk.py
+++ b/src/calibre/gui2/dialogs/metadata_bulk.py
@@ -372,13 +372,13 @@ class MetadataBulkDialog(ResizableDialog, Ui_MetadataBulkDialog):
         self.apply_pubdate.setChecked(True)
 
     def clear_pubdate(self, *args):
-        self.pubdate.setMinimumDateTime(UNDEFINED_QDATETIME)
+        self.pubdate.setDateTime(UNDEFINED_QDATETIME)
 
     def do_apply_adddate(self, *args):
         self.apply_adddate.setChecked(True)
 
     def clear_adddate(self, *args):
-        self.adddate.setMinimumDateTime(UNDEFINED_QDATETIME)
+        self.adddate.setDateTime(UNDEFINED_QDATETIME)
 
     def button_clicked(self, which):
         if which == self.button_box.button(QDialogButtonBox.Apply):
diff --git a/src/calibre/utils/date.py b/src/calibre/utils/date.py
index 0de50e4122..faac8795d4 100644
--- a/src/calibre/utils/date.py
+++ b/src/calibre/utils/date.py
@@ -291,6 +291,11 @@ def clean_date_for_sort(dt, format):
     if not isinstance(dt, datetime):
         dt = datetime.combine(dt, time())
 
+    if hasattr(dt, 'tzinfo'):
+        if dt.tzinfo is None:
+            dt = dt.replace(tzinfo=_local_tz)
+        dt = as_local_time(dt)
+
     if format == 'iso':
         format = 'yyMdhms'