From 5a276bde86201a863dbdc52b5e0790db074586fd Mon Sep 17 00:00:00 2001
From: Eric Larson <larson.eric.d@gmail.com>
Date: Wed, 9 Aug 2023 15:10:04 -0400
Subject: [PATCH] FIX: Tolerate huge year

---
 sphinx/environment/__init__.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sphinx/environment/__init__.py b/sphinx/environment/__init__.py
index 3dbc5932b6a..37472387ddd 100644
--- a/sphinx/environment/__init__.py
+++ b/sphinx/environment/__init__.py
@@ -511,13 +511,17 @@ def get_outdated_files(self, config_changed: bool) -> tuple[set[str], set[str],
                             break
                         depmtime = _last_modified_time(deppath)
                         if depmtime > mtime:
+                            try:
+                                depmtime_dt = datetime.utcfromtimestamp(depmtime)
+                            except ValueError:  # e.g., year 53606865 is out of range
+                                depmtime_dt = depmtime
                             logger.debug(
                                 '[build target] outdated %r '
                                 'from dependency %r: %s -> %s',
                                 docname,
                                 deppath,
                                 datetime.utcfromtimestamp(mtime),
-                                datetime.utcfromtimestamp(depmtime))
+                                depmtime_dt)
                             changed.add(docname)
                             break
                     except OSError: