diff --git a/build_docs.py b/build_docs.py
index 255f45d..58836e4 100755
--- a/build_docs.py
+++ b/build_docs.py
@@ -610,16 +610,21 @@ def full_build(self):
     def run(self, http: urllib3.PoolManager) -> bool:
         """Build and publish a Python doc, for a language, and a version."""
         start_time = perf_counter()
+        start_timestamp = dt.now(tz=timezone.utc).replace(microsecond=0)
         logging.info("Running.")
         try:
             self.cpython_repo.switch(self.version.branch_or_tag)
             if self.language.tag != "en":
                 self.clone_translation()
-            if self.should_rebuild():
+            if trigger_reason := self.should_rebuild():
                 self.build_venv()
                 self.build()
                 self.copy_build_to_webroot(http)
-                self.save_state(build_duration=perf_counter() - start_time)
+                self.save_state(
+                    build_start=start_timestamp,
+                    build_duration=perf_counter() - start_time,
+                    trigger=trigger_reason,
+                )
         except Exception as err:
             logging.exception("Badly handled exception, human, please help.")
             if sentry_sdk:
@@ -885,7 +890,7 @@ def should_rebuild(self):
         state = self.load_state()
         if not state:
             logging.info("Should rebuild: no previous state found.")
-            return True
+            return "no previous state"
         cpython_sha = self.cpython_repo.run("rev-parse", "HEAD").stdout.strip()
         if self.language.tag != "en":
             translation_sha = self.translation_repo.run(
@@ -897,7 +902,7 @@ def should_rebuild(self):
                     state["translation_sha"],
                     translation_sha,
                 )
-                return True
+                return "new translations"
         if cpython_sha != state["cpython_sha"]:
             diff = self.cpython_repo.run(
                 "diff", "--name-only", state["cpython_sha"], cpython_sha
@@ -908,7 +913,7 @@ def should_rebuild(self):
                     state["cpython_sha"],
                     cpython_sha,
                 )
-                return True
+                return "Doc/ has changed"
         logging.info("Nothing changed, no rebuild needed.")
         return False
 
@@ -921,7 +926,7 @@ def load_state(self) -> dict:
         except (KeyError, FileNotFoundError):
             return {}
 
-    def save_state(self, build_duration: float):
+    def save_state(self, build_start: dt, build_duration: float, trigger: str):
         """Save current CPython sha1 and current translation sha1.
 
         Using this we can deduce if a rebuild is needed or not.
@@ -932,17 +937,24 @@ def save_state(self, build_duration: float):
         except FileNotFoundError:
             states = tomlkit.document()
 
-        state = {}
-        state["cpython_sha"] = self.cpython_repo.run("rev-parse", "HEAD").stdout.strip()
+        key = f"/{self.language.tag}/{self.version.name}/"
+        state = {
+            "last_build_start": build_start,
+            "last_build_duration": round(build_duration, 0),
+            "triggered_by": trigger,
+            "cpython_sha": self.cpython_repo.run("rev-parse", "HEAD").stdout.strip(),
+        }
         if self.language.tag != "en":
             state["translation_sha"] = self.translation_repo.run(
                 "rev-parse", "HEAD"
             ).stdout.strip()
-        state["last_build"] = dt.now(timezone.utc)
-        state["last_build_duration"] = build_duration
-        states[f"/{self.language.tag}/{self.version.name}/"] = state
+        states[key] = state
         state_file.write_text(tomlkit.dumps(states), encoding="UTF-8")
 
+        table = tomlkit.inline_table()
+        table |= state
+        logging.info("Saved new rebuild state for %s: %s", key, table.as_string())
+
 
 def symlink(
     www_root: Path,