diff --git a/babel/messages/catalog.py b/babel/messages/catalog.py
index 9a9739a72..05fa41b3c 100644
--- a/babel/messages/catalog.py
+++ b/babel/messages/catalog.py
@@ -582,10 +582,11 @@ def _set_mime_headers(self, headers: Iterable[tuple[str, str]]) -> None:
                 self._num_plurals = int(params.get('nplurals', 2))
                 self._plural_expr = params.get('plural', '(n != 1)')
             elif name == 'pot-creation-date':
-                self.creation_date = _parse_datetime_header(value)
+                if value.strip():
+                    self.creation_date = _parse_datetime_header(value)
             elif name == 'po-revision-date':
                 # Keep the value if it's not the default one
-                if 'YEAR' not in value:
+                if 'YEAR' not in value and value.strip():
                     self.revision_date = _parse_datetime_header(value)
 
     mime_headers = property(