diff --git a/main.py b/main.py
index 022cb95..9e2b390 100644
--- a/main.py
+++ b/main.py
@@ -4,6 +4,7 @@ import json
 import google_reader
 import tomllib
 import sys
+import argparse
 from datetime import datetime
 from zoneinfo import ZoneInfo
 from pathlib import Path
@@ -102,13 +103,13 @@ def mark_deleted_as_read(config, client_session):
 
     marked_as_read = 0
     to_mark_as_read = []
-    for stored_item in config.json_root.glob("*.json"):
-        item_json = json.load(stored_item.open("r"))
+    for json_path in config.json_root.glob("*.json"):
+        item_json = json.load(json_path.open("r"))
         html_path = config.html_root / item_json["html_path"]
         if not html_path.exists():
             to_mark_as_read.append(item_json["id"])
             # delete JSON file
-            stored_item.unlink()
+            json_path.unlink()
             marked_as_read += 1
 
     for i in range(0, len(to_mark_as_read), config.items_per_query):
@@ -141,6 +142,11 @@ def get_html_path(config, item_json):
 def format_datetime(config, timestamp):
     return datetime.fromtimestamp(timestamp, config.timezone).strftime(config.time_format)
 
+def set_computed_fields_json(config, item_json):
+    item_json["published_formatted"] = format_datetime(config, item_json["published"])
+    item_json["updated_formatted"] = format_datetime(config, item_json["updated"])
+    item_json["html_path"] = str(get_html_path(config, item_json).relative_to(config.html_root))
+
 def synchronize_with_server(config, client_session):
     # Synchronize items from the server, generating and deleting JSON and HTML files accordingly
     config.update_lock.touch()
@@ -163,9 +169,7 @@ def synchronize_with_server(config, client_session):
                         "folder": folder_name,
                         "title": item_content.title,
                         "published": item_content.published,
-                        "published_formatted": format_datetime(config, item_content.published),
                         "updated": item_content.updated,
-                        "updated_formatted": format_datetime(config, item_content.updated),
                         "author": item_content.author,
                         "summary": item_content.summary.content,
                         "content": item_content.content.content,
@@ -173,7 +177,7 @@ def synchronize_with_server(config, client_session):
                         "origin_url": item_content.origin.html_url,
                         "canonical_url": item_content.canonical[0].href,
                     }
-                    item_json["html_path"] = str(get_html_path(config, item_json).relative_to(config.html_root))
+                    set_computed_fields_json(config, item_json)
 
                     json_path = config.json_root / f"{ sha256(item_json["id"].encode("utf-8")).hexdigest() }.json"
                     grabbed_item_paths.append(json_path)
@@ -240,18 +244,42 @@ def remove_empty_html_directories(config):
             if len(dirnames) == 0 and len(filenames) == 0:
                 dirpath.rmdir()
 
-def process(config, client_session):
+def update(config, client_session):
     # Do a full feather update
     mark_deleted_as_read(config, client_session)
     synchronize_with_server(config, client_session)
     remove_empty_html_directories(config)
 
+def regenerate_files(config):
+    for json_path in config.json_root.glob("*.json"):
+        item_json = json.load(json_path.open("r"))
+        remove_html_for_item(config, item_json, ignore_deleted=True) # path might change so we preemptively remove the old file
+        set_computed_fields_json(config, item_json) # recompute formatted datetime & path from the current configuration
+        # rewrite JSON
+        with json_path.open("w") as f:
+            json.dump(item_json, f)
+        # rewrite HTML
+        generate_html_for_item(config, item_json, regenerate=True)
+
 #%% Run feather
 
 def main():
+    parser = argparse.ArgumentParser(
+        prog="feather",
+        description="file-based RSS reader"
+    )
+    parser.add_argument(
+        "action", choices=("update", "regenerate"),
+        help='''use update to perform a full synchronization with the server; regenerate will regenerate all HTML files from the local data'''
+    )
+    args = parser.parse_args()
+
     config = Config()
-    client_session = ClientSession(config)
-    process(config, client_session)
+    if args.action == "update":
+        client_session = ClientSession(config)
+        update(config, client_session)
+    elif args.action == "regenerate":
+        regenerate_files(config)
 
 if __name__ == "__main__":
     main()