diff --git a/swh/clearlydefined/tests/test_mapping_utils.py b/swh/clearlydefined/tests/test_mapping_utils.py
index 04da8a8..3d50576 100644
--- a/swh/clearlydefined/tests/test_mapping_utils.py
+++ b/swh/clearlydefined/tests/test_mapping_utils.py
@@ -1,587 +1,567 @@
 # Copyright (C) 2021 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU Affero General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from datetime import datetime, timezone
+from datetime import datetime, timedelta, timezone
 import gzip
 import json
 import os
 
 import pytest
 
 from swh.clearlydefined.error import (
     InvalidComponents,
     NoJsonExtension,
     RevisionNotFound,
     ToolNotFound,
     ToolNotSupported,
 )
 from swh.clearlydefined.mapping_utils import (
     AUTHORITY,
     FETCHER,
     MappingStatus,
     map_definition,
     map_row,
     map_sha1_with_swhid,
 )
 from swh.model import from_disk
 from swh.model.hashutil import hash_to_bytes
 from swh.model.swhids import ExtendedSWHID
 from swh.model.model import (
     Content,
     Directory,
     DirectoryEntry,
     Person,
     RawExtrinsicMetadata,
     Revision,
     RevisionType,
     Timestamp,
     TimestampWithTimezone,
 )
 
 content_data = [
     Content.from_data(b"42\n"),
     Content.from_data(b"4242\n"),
 ]
 
 directory = Directory(
     id=hash_to_bytes("5256e856a0a0898966d6ba14feb4388b8b82d302"),
     entries=tuple(
         [
             DirectoryEntry(
                 name=b"foo",
                 type="file",
                 target=content_data[0].sha1_git,
                 perms=from_disk.DentryPerms.content,
             ),
         ],
     ),
 )
 
 revision_data = [
     Revision(
         id=hash_to_bytes("4c66129b968ab8122964823d1d77677f50884cf6"),
         message=b"hello",
         author=Person(
             name=b"Nicolas Dandrimont",
             email=b"nicolas@example.com",
             fullname=b"Nicolas Dandrimont <nicolas@example.com> ",
         ),
-        date=TimestampWithTimezone(
-            timestamp=Timestamp(seconds=1234567890, microseconds=0),
-            offset=120,
-            negative_utc=False,
-        ),
+        date=TimestampWithTimezone.from_datetime(datetime(2009, 2, 14, 1, 31, 30, tzinfo=timezone(timedelta(seconds=7200))))
+,
         committer=Person(
             name=b"St\xc3fano Zacchiroli",
             email=b"stefano@example.com",
             fullname=b"St\xc3fano Zacchiroli <stefano@example.com>",
         ),
-        committer_date=TimestampWithTimezone(
-            timestamp=Timestamp(seconds=1123456789, microseconds=0),
-            offset=120,
-            negative_utc=False,
-        ),
+        committer_date=TimestampWithTimezone.from_datetime(datetime(2005, 8, 8, 1, 19, 49, tzinfo=timezone(timedelta(seconds=7200))))
+,
         parents=(),
         type=RevisionType.GIT,
         directory=directory.id,
         metadata={
             "checksums": {
                 "sha1": "tarball-sha1",
                 "sha256": "tarball-sha256",
             },
             "signed-off-by": "some-dude",
         },
         extra_headers=(
             (b"gpgsig", b"test123"),
             (b"mergetag", b"foo\\bar"),
             (b"mergetag", b"\x22\xaf\x89\x80\x01\x00"),
         ),
         synthetic=True,
     ),
     Revision(
         id=hash_to_bytes("3c66129b968ab8122964823d1d77677f50884cf6"),
         message=b"hello again",
         author=Person(
             name=b"Roberto Dicosmo",
             email=b"roberto@example.com",
             fullname=b"Roberto Dicosmo <roberto@example.com>",
         ),
-        date=TimestampWithTimezone(
-            timestamp=Timestamp(
-                seconds=1234567843,
-                microseconds=220000,
-            ),
-            offset=-720,
-            negative_utc=False,
-        ),
+        date=TimestampWithTimezone.from_datetime(datetime(2009, 2, 13, 11, 30, 43, 220000, tzinfo=timezone(timedelta(days=-1, seconds=43200)))),
         committer=Person(
             name=b"tony",
             email=b"ar@dumont.fr",
             fullname=b"tony <ar@dumont.fr>",
         ),
-        committer_date=TimestampWithTimezone(
-            timestamp=Timestamp(
-                seconds=1123456789,
-                microseconds=220000,
-            ),
-            offset=0,
-            negative_utc=False,
-        ),
+        committer_date=TimestampWithTimezone.from_datetime(datetime(2005, 8, 7, 23, 19, 49, 220000, tzinfo=timezone.utc)),
         parents=(),
         type=RevisionType.GIT,
         directory=directory.id,
         metadata=None,
         extra_headers=(),
         synthetic=False,
     ),
 ]
 
 
 def file_data(file_name):
     with open(file_name) as file:
         data = file.read()
         return data
 
 
 def add_content_data(swh_storage):
     swh_storage.content_add(content_data)
 
 
 def add_revision_data(swh_storage):
     swh_storage.revision_add(revision_data)
 
 
 def test_mapping_sha1_with_swhID(swh_storage):
     add_content_data(swh_storage)
     sha1 = "34973274ccef6ab4dfaaf86599792fa9c3fe4689"
     assert "swh:1:cnt:d81cc0710eb6cf9efd5b920a8453e1e07157b6cd" == str(
         map_sha1_with_swhid(sha1=sha1, storage=swh_storage)
     )
 
 
 def test_mapping_with_empty_sha1(swh_storage):
     add_content_data(swh_storage)
     sha1 = ""
     assert map_sha1_with_swhid(sha1=sha1, storage=swh_storage) is None
 
 
 def test_mapping_with_wrong_sha1(swh_storage):
     add_content_data(swh_storage)
     sha1 = "6ac599151a7aaa8ca5d38dc5bb61b49193a3cadc1ed33de5a57e4d1ecc53c846"
     assert map_sha1_with_swhid(sha1=sha1, storage=swh_storage) is None
 
 
 def test_map_row_for_definitions_with_no_sha1_sha1git(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = MappingStatus.UNMAPPED, []
     assert (
         map_row(
             storage=swh_storage,
             id="maven/mavencentral/za.co.absa.cobrix/cobol-parser/revision/0.4.0.json",
             metadata=gzip.compress(
                 file_data(
                     os.path.join(datadir, "def_with_no_sha1_and_sha1git.json")
                 ).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_for_definitions_with_gitsha1(swh_storage, datadir):
     add_revision_data(swh_storage)
     expected = (
         MappingStatus.MAPPED,
         [
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:rev:4c66129b968ab8122964823d1d77677f50884cf6"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-definition-json",
                 origin="http://central.maven.org/maven2/za/co/absa/cobrix/cobol-parser/"
                 "0.4.0/cobol-parser-0.4.0-sources.jar",
                 metadata=json.dumps(
                     json.loads(
                         file_data(os.path.join(datadir, "definitions_sha1git.json"))
                     )
                 ).encode("utf-8"),
             ),
         ],
     )
     assert (
         map_row(
             storage=swh_storage,
             id="maven/mavencentral/za.co.absa.cobrix/cobol-parser/revision/0.4.0.json",
             metadata=gzip.compress(
                 file_data(os.path.join(datadir, "definitions_sha1git.json")).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_for_scancode(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = (
         MappingStatus.UNMAPPED,
         [
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:d81cc0710eb6cf9efd5b920a8453e1e07157b6cd"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-scancode-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(os.path.join(datadir, "scancode_metadata.json"))
                     )
                 ).encode("utf-8"),
             ),
         ],
     )
     assert (
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@ngtools/webpack/revision/10.2.1/tool/scancode/3.2.2.json",
             metadata=gzip.compress(
                 file_data(os.path.join(datadir, "scancode.json")).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_for_scancode_true_mapping_status(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = (
         MappingStatus.MAPPED,
         [
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:d81cc0710eb6cf9efd5b920a8453e1e07157b6cd"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-scancode-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(os.path.join(datadir, "scancode_metadata.json"))
                     )
                 ).encode("utf-8"),
             ),
         ],
     )
     assert (
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@ngtools/webpack/revision/10.2.1/tool/scancode/3.2.2.json",
             metadata=gzip.compress(
                 file_data(os.path.join(datadir, "scancode_true.json")).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_for_licensee(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = (
         MappingStatus.UNMAPPED,
         [
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:36fade77193cb6d2bd826161a0979d64c28ab4fa"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-licensee-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(os.path.join(datadir, "licensee_metadata.json"))
                     )
                 ).encode("utf-8"),
             ),
         ],
     )
     assert (
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@fluidframework/replay-driver/revision/0.31.0/tool/licensee/"
             "9.13.0.json",
             metadata=gzip.compress(
                 file_data(os.path.join(datadir, "licensee.json")).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_for_licensee_true_mapping_status(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = (
         MappingStatus.MAPPED,
         [
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:36fade77193cb6d2bd826161a0979d64c28ab4fa"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-licensee-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(os.path.join(datadir, "licensee_metadata.json"))
                     )
                 ).encode("utf-8"),
             ),
         ],
     )
     assert (
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@fluidframework/replay-driver/revision/0.31.0/tool/licensee/"
             "9.13.0.json",
             metadata=gzip.compress(
                 file_data(os.path.join(datadir, "licensee_true.json")).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_for_clearlydefined(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = (
         MappingStatus.UNMAPPED,
         [
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:36fade77193cb6d2bd826161a0979d64c28ab4fa"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-clearlydefined-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(os.path.join(datadir, "clearlydefined_metadata.json"))
                     )
                 ).encode("utf-8"),
             ),
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:d81cc0710eb6cf9efd5b920a8453e1e07157b6cd"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-clearlydefined-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(
                             os.path.join(datadir, "clearlydefined_metadata_2.json")
                         )
                     )
                 ).encode("utf-8"),
             ),
         ],
     )
     assert (
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@pixi/mesh-extras/revision/5.3.5/tool/clearlydefined/"
             "1.3.4.json",
             metadata=gzip.compress(
                 file_data(os.path.join(datadir, "clearlydefined.json")).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_for_clearlydefined_true_mapping_status(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = (
         MappingStatus.MAPPED,
         [
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:36fade77193cb6d2bd826161a0979d64c28ab4fa"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-clearlydefined-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(os.path.join(datadir, "clearlydefined_metadata.json"))
                     )
                 ).encode("utf-8"),
             ),
             RawExtrinsicMetadata(
                 target=ExtendedSWHID.from_string(
                     "swh:1:cnt:d81cc0710eb6cf9efd5b920a8453e1e07157b6cd"
                 ),
                 discovery_date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
                 authority=AUTHORITY,
                 fetcher=FETCHER,
                 format="clearlydefined-harvest-clearlydefined-json",
                 origin=None,
                 metadata=json.dumps(
                     json.loads(
                         file_data(
                             os.path.join(datadir, "clearlydefined_metadata_2.json")
                         )
                     )
                 ).encode("utf-8"),
             ),
         ],
     )
     assert (
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@pixi/mesh-extras/revision/5.3.5/tool/clearlydefined/"
             "1.3.4.json",
             metadata=gzip.compress(
                 file_data(os.path.join(datadir, "clearlydefined_true.json")).encode()
             ),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_sha1git_not_in_revision(swh_storage, datadir):
     add_revision_data(swh_storage)
     expected = MappingStatus.UNMAPPED, []
     assert (
         map_definition(
             metadata_string=file_data(
                 os.path.join(datadir, "definitions_not_mapped_sha1_git.json")
             ),
             storage=swh_storage,
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_sha1_not_in_content(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = MappingStatus.IGNORE, []
     assert (
         map_definition(
             metadata_string=file_data(
                 os.path.join(datadir, "definitions_not_mapped.json")
             ),
             storage=swh_storage,
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_definition_with_data_to_be_ignored(swh_storage, datadir):
     add_content_data(swh_storage)
     expected = MappingStatus.IGNORE, []
     assert (
         map_definition(
             metadata_string=file_data(os.path.join(datadir, "licensee.json")),
             storage=swh_storage,
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
         == expected
     )
 
 
 def test_map_row_with_invalid_ID(swh_storage):
     with pytest.raises(InvalidComponents):
         map_row(
             storage=swh_storage,
             id="maven/mavencentral/cobol-parser/abc/revision/def/0.4.0.json",
             metadata=gzip.compress(" ".encode()),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
 
 
 def test_map_row_with_empty_metadata_string(swh_storage):
     map_row(
         storage=swh_storage,
         id="maven/mavencentral/za.co.absa.cobrix/cobol-parser/revision/0.4.0.json",
         metadata=gzip.compress("".encode()),
         date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
     ) is None
 
 
 def test_map_row_with_invalid_ID_without_revision(swh_storage):
     with pytest.raises(RevisionNotFound):
         map_row(
             storage=swh_storage,
             id="maven/mavencentral/za.co.absa.cobrix/cobol-parser/abc/0.4.0.json",
             metadata=gzip.compress("".encode()),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
 
 
 def test_map_row_with_invalid_ID_without_json_extension(swh_storage):
     with pytest.raises(NoJsonExtension):
         map_row(
             storage=swh_storage,
             id="maven/mavencentral/za.co.absa.cobrix/cobol-parser/revision/0.4.0.txt",
             metadata=gzip.compress("".encode()),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
 
 
 def test_map_row_with_invalid_ID_without_6_or_9_length(swh_storage):
     with pytest.raises(InvalidComponents):
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@ngtools/webpack/revision/10.2.1/tool/3.2.2.json",
             metadata=gzip.compress("".encode()),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
 
 
 def test_map_row_with_invalid_tool(swh_storage):
     with pytest.raises(ToolNotSupported):
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@ngtools/webpack/revision/10.2.1/tool/abc/3.2.2.json",
             metadata=gzip.compress("".encode()),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )
 
 
 def test_map_row_with_invalid_harvest_ID(swh_storage):
     with pytest.raises(ToolNotFound):
         map_row(
             storage=swh_storage,
             id="npm/npmjs/@ngtools/webpack/revision/10.2.1/abc/scancode/3.2.2.json",
             metadata=gzip.compress("".encode()),
             date=datetime(year=2021, month=2, day=6, tzinfo=timezone.utc),
         )