diff --git a/docs/Makefile.local b/docs/Makefile.local
--- a/docs/Makefile.local
+++ b/docs/Makefile.local
@@ -1,27 +0,0 @@
-sphinx/html: sql-autodoc images
-sphinx/clean: clean-sql-autodoc clean-images
-assets: sql-autodoc images
-
-sql-autodoc:
-	make -C ../sql/ doc
-	cp ../sql/doc/sql/db-schema.svg images/
-
-images:
-	make -C images/
-clean-images:
-	make -C images/ clean
-
-clean: clean-sql-autodoc clean-images
-clean-sql-autodoc:
-	make -C ../sql/ clean
-
-distclean: clean distclean-sql-autodoc
-distclean-sql-autodoc:
-	make -C ../sql/ distclean
-
-.PHONY: sql-autodoc clean-sql-autodoc images clean-images
-
-
-# Local Variables:
-# mode: makefile
-# End:
diff --git a/sql/upgrades/180.sql b/sql/upgrades/180.sql
--- a/sql/upgrades/180.sql
+++ b/sql/upgrades/180.sql
@@ -1,5 +1,5 @@
 -- SWH DB schema upgrade
--- from_version: 177
+-- from_version: 179
 -- to_version: 180
 -- description: add {,committer_}date_offset_bytes to rev/rel + raw_manifest to dir/rev/rel, part 2
 
diff --git a/sql/upgrades/182.sql b/sql/upgrades/182.sql
new file mode 100644
--- /dev/null
+++ b/sql/upgrades/182.sql
@@ -0,0 +1,22 @@
+-- SWH DB schema upgrade
+-- from_version: 181
+-- to_version: 182
+-- description: fix null date_offset_bytes and remove leftover function from 180.sql
+
+insert into dbversion(version, release, description)
+    values(182, now(), 'Work In Progress');
+
+
+update release
+    set date_offset_bytes='+0000'::bytea
+    where date is not null and date_offset_bytes is null;
+
+update revision
+    set date_offset_bytes='+0000'::bytea
+    where (date = 0 and date_neg_utc_offset is null and date_offset_bytes is null)
+
+update revision
+    set committer_date_offset_bytes='+0000'::bytea
+    where (committer_date = 0 and committer_date_neg_utc_offset is null and committer_date_offset_bytes is null)
+
+drop function if exists _format_offset;
diff --git a/swh/storage/postgresql/db.py b/swh/storage/postgresql/db.py
--- a/swh/storage/postgresql/db.py
+++ b/swh/storage/postgresql/db.py
@@ -30,7 +30,7 @@
 
     """
 
-    current_version = 181
+    current_version = 182
 
     def mktemp_dir_entry(self, entry_type, cur=None):
         self._cursor(cur).execute(