Take advantage of the fact that find_files now sorts files by timestamp.

gemfeed.py

@@ -109,14 +109,12 @@ def main():
 
     # Add one entry per .gmi file
     files = find_files(args.n)
-    latest_update = datetime.datetime.fromtimestamp(0, tz=datetime.timezone.utc)
-    for filename in files:
+    for n, filename in enumerate(files):
         entry = feed.add_entry()
         populate_entry_from_file(filename, args.base_url, entry)
         print("Adding {} with title '{}'...".format(filename, entry.title()))
-        if entry.updated() > latest_update:
-            latest_update = entry.updated()
-    feed.updated(latest_update)
+        if n == 0:
+            feed.updated(entry.updated())
 
     # Write file
     feed.atom_file(args.output, pretty=True)