diff --git a/swh/graphql/app.py b/swh/graphql/app.py
--- a/swh/graphql/app.py
+++ b/swh/graphql/app.py
@@ -36,6 +36,7 @@
     resolvers.directory_entry_target,
     resolvers.search_result_target,
     resolvers.binary_string,
+    resolvers.date,
     scalars.id_scalar,
     scalars.datetime_scalar,
     scalars.swhid_scalar,
diff --git a/swh/graphql/resolvers/resolvers.py b/swh/graphql/resolvers/resolvers.py
--- a/swh/graphql/resolvers/resolvers.py
+++ b/swh/graphql/resolvers/resolvers.py
@@ -16,6 +16,7 @@
 #   Every scalar is expected to resolve this way
 # - As an attribute/item in the object/dict returned by a backend (eg: Origin.url)
 
+import datetime
 from typing import Optional, Union
 
 from ariadne import ObjectType, UnionType
@@ -23,6 +24,7 @@
 
 from swh.graphql import resolvers as rs
 from swh.graphql.utils import utils
+from swh.model.model import TimestampWithTimezone
 
 from .resolver_factory import ConnectionObjectFactory, NodeObjectFactory
 
@@ -38,6 +40,7 @@
 directory_entry: ObjectType = ObjectType("DirectoryEntry")
 search_result: ObjectType = ObjectType("SearchResult")
 binary_string: ObjectType = ObjectType("BinaryString")
+date: ObjectType = ObjectType("Date")
 
 branch_target: UnionType = UnionType("BranchTarget")
 release_target: UnionType = UnionType("ReleaseTarget")
@@ -312,3 +315,22 @@
 @binary_string.field("base64")
 def binary_string_base64_resolver(obj: bytes, *args, **kw) -> str:
     return utils.get_b64_string(obj)
+
+
+# Date object resolver
+
+
+@date.field("date")
+def date_date_resolver(
+    obj: TimestampWithTimezone, *args: GraphQLResolveInfo, **kw
+) -> datetime.datetime:
+    # This will be serialised as a DateTime Scalar
+    return obj.to_datetime()
+
+
+@date.field("offset")
+def date_offset_resolver(
+    obj: TimestampWithTimezone, *args: GraphQLResolveInfo, **kw
+) -> bytes:
+    # This will be serialised as a Binary string
+    return obj.offset_bytes
diff --git a/swh/graphql/resolvers/revision.py b/swh/graphql/resolvers/revision.py
--- a/swh/graphql/resolvers/revision.py
+++ b/swh/graphql/resolvers/revision.py
@@ -37,6 +37,10 @@
     def directory_hash(self):  # for RevisionDirectoryNode resolver
         return self._node.directory
 
+    @property
+    def committerDate(self):  # To support the schema naming convention
+        return self._node.committer_date
+
     @property
     def type(self):
         return self._node.type.value
diff --git a/swh/graphql/resolvers/scalars.py b/swh/graphql/resolvers/scalars.py
--- a/swh/graphql/resolvers/scalars.py
+++ b/swh/graphql/resolvers/scalars.py
@@ -3,14 +3,14 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from datetime import datetime
+import datetime
+from typing import Optional
 
 from ariadne import ScalarType
 
 from swh.graphql.errors import InvalidInputError
 from swh.graphql.utils import utils
 from swh.model.exceptions import ValidationError
-from swh.model.model import TimestampWithTimezone
 from swh.model.swhids import CoreSWHID
 
 datetime_scalar = ScalarType("DateTime")
@@ -26,13 +26,8 @@
 
 
 @datetime_scalar.serializer
-def serialize_datetime(value):
-    # FIXME, handle error and return None
-    if type(value) == TimestampWithTimezone:
-        value = value.to_datetime()
-    if type(value) == datetime:
-        return utils.get_formatted_date(value)
-    return None
+def serialize_datetime(value: Optional[datetime.datetime]) -> Optional[str]:
+    return utils.get_formatted_date(value) if type(value) == datetime.datetime else None
 
 
 @swhid_scalar.value_parser
diff --git a/swh/graphql/schema/schema.graphql b/swh/graphql/schema/schema.graphql
--- a/swh/graphql/schema/schema.graphql
+++ b/swh/graphql/schema/schema.graphql
@@ -570,6 +570,21 @@
   node: Revision
 }
 
+"""
+Object with Date values
+"""
+type Date {
+  """
+  ISO-8601 encoded date string.
+  """
+  date: DateTime
+
+  """
+  UTC offset
+  """
+  offset: BinaryString
+}
+
 """
 A revision object
 """
@@ -600,9 +615,14 @@
   committer: Person
 
   """
-  Revision date ISO-8601 encoded
+  Commit date
   """
-  date: DateTime
+  committerDate: Date
+
+  """
+  Revision date
+  """
+  date: Date
 
   """
   Type of the revision, eg: git/hg
@@ -691,9 +711,9 @@
   author: Person
 
   """
-  Release date ISO-8601 encoded
+  Release date
   """
-  date: DateTime
+  date: Date
 
   """
   Type of release target
diff --git a/swh/graphql/tests/data.py b/swh/graphql/tests/data.py
--- a/swh/graphql/tests/data.py
+++ b/swh/graphql/tests/data.py
@@ -112,6 +112,22 @@
     ]
 
 
+def get_revisions_with_none_date():
+    return [
+        Revision(
+            message=b"hello",
+            date=None,
+            committer=swh_model_data.COMMITTERS[0],
+            author=swh_model_data.COMMITTERS[0],
+            committer_date=swh_model_data.DATES[0],
+            type=RevisionType.GIT,
+            directory=b"\x01" * 20,
+            synthetic=False,
+            parents=(get_revisions()[0].id, get_revisions()[1].id),
+        )
+    ]
+
+
 def get_directories_with_nested_path():
     return [
         Directory(
@@ -158,7 +174,7 @@
 
 GRAPHQL_EXTRA_TEST_OBJECTS = {
     "release": get_releases_with_target(),
-    "revision": get_revisions_with_parents(),
+    "revision": get_revisions_with_parents() + get_revisions_with_none_date(),
     "directory": get_directories_with_nested_path()
     + get_directories_with_special_name_entries(),
     "origin_visit_status": get_visit_with_multiple_status(),
diff --git a/swh/graphql/tests/functional/test_release_node.py b/swh/graphql/tests/functional/test_release_node.py
--- a/swh/graphql/tests/functional/test_release_node.py
+++ b/swh/graphql/tests/functional/test_release_node.py
@@ -43,7 +43,13 @@
             text
           }
         }
-        date
+        date {
+          date
+          offset {
+            text
+            base64
+          }
+        }
         targetType
       }
     }
@@ -64,7 +70,15 @@
         }
         if release.author
         else None,
-        "date": release.date.to_datetime().isoformat() if release.date else None,
+        "date": {
+            "date": release.date.to_datetime().isoformat(),
+            "offset": {
+                "text": release.date.offset_bytes.decode(),
+                "base64": base64.b64encode(release.date.offset_bytes).decode("ascii"),
+            },
+        }
+        if release.date
+        else None,
         "targetType": release.target_type.value,
     }
 
diff --git a/swh/graphql/tests/functional/test_revision.py b/swh/graphql/tests/functional/test_revision.py
--- a/swh/graphql/tests/functional/test_revision.py
+++ b/swh/graphql/tests/functional/test_revision.py
@@ -3,12 +3,18 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+import base64
+
 import pytest
 
 from swh.model.swhids import CoreSWHID
 
 from . import utils
-from ..data import get_revisions, get_revisions_with_parents
+from ..data import (
+    get_revisions,
+    get_revisions_with_none_date,
+    get_revisions_with_parents,
+)
 
 
 @pytest.mark.parametrize("revision", get_revisions())
@@ -42,7 +48,20 @@
             text
           }
         }
-        date
+        date {
+          date
+          offset {
+            text
+            base64
+          }
+        }
+        committerDate {
+          date
+          offset {
+            text
+            base64
+          }
+        }
         type
         directory {
           swhid
@@ -51,6 +70,7 @@
     }
     """
     data, _ = utils.get_query_response(client, query_str, swhid=str(revision.swhid()))
+
     assert data["revision"] == {
         "swhid": str(revision.swhid()),
         "message": {"text": revision.message.decode()},
@@ -64,7 +84,26 @@
             "name": {"text": revision.committer.name.decode()},
             "email": {"text": revision.committer.email.decode()},
         },
-        "date": revision.date.to_datetime().isoformat(),
+        "date": {
+            "date": revision.date.to_datetime().isoformat(),
+            "offset": {
+                "text": revision.date.offset_bytes.decode(),
+                "base64": base64.b64encode(revision.date.offset_bytes).decode("ascii"),
+            },
+        }
+        if revision.date
+        else None,
+        "committerDate": {
+            "date": revision.committer_date.to_datetime().isoformat(),
+            "offset": {
+                "text": revision.committer_date.offset_bytes.decode(),
+                "base64": base64.b64encode(revision.committer_date.offset_bytes).decode(
+                    "ascii"
+                ),
+            },
+        }
+        if revision.committer_date
+        else None,
         "type": revision.type.value,
         "directory": {
             "swhid": str(CoreSWHID(object_id=revision.directory, object_type="dir"))
@@ -175,3 +214,23 @@
         obj_type="revision",
         swhid=f"swh:1:rev:{unknown_sha1}",
     )
+
+
+def test_get_revisions_with_none_date(client):
+    revision_swhid = get_revisions_with_none_date()[0].swhid()
+    query_str = """
+    query getRevision($swhid: SWHID!) {
+      revision(swhid: $swhid) {
+        swhid
+        date {
+          date
+          offset {
+            text
+            base64
+          }
+        }
+      }
+    }
+    """
+    data, _ = utils.get_query_response(client, query_str, swhid=str(revision_swhid))
+    assert data == {"revision": {"swhid": str(revision_swhid), "date": None}}
diff --git a/swh/graphql/tests/unit/resolvers/test_scalars.py b/swh/graphql/tests/unit/resolvers/test_scalars.py
--- a/swh/graphql/tests/unit/resolvers/test_scalars.py
+++ b/swh/graphql/tests/unit/resolvers/test_scalars.py
@@ -16,14 +16,6 @@
     assert scalars.serialize_id(b"test") == "74657374"
 
 
-def test_serialize_datetime():
-    assert scalars.serialize_datetime("invalid") is None
-    # python datetime
-    date = datetime.datetime(2020, 5, 17)
-    assert scalars.serialize_datetime(date) == date.isoformat()
-    # FIXME, Timestamp with timezone
-
-
 def test_validate_swhid_invalid():
     with pytest.raises(InvalidInputError):
         scalars.validate_swhid("invalid")
@@ -32,3 +24,12 @@
 def test_validate_swhid():
     swhid = scalars.validate_swhid(f"swh:1:rev:{'1' * 40}")
     assert str(swhid) == "swh:1:rev:1111111111111111111111111111111111111111"
+
+
+def test_serialize_datetime_from_datetime():
+    dt = datetime.datetime(2010, 1, 15, 2, 12, 10, 2, datetime.timezone.utc)
+    assert scalars.serialize_datetime(dt) == "2010-01-15T02:12:10.000002+00:00"
+
+
+def test_serialize_datetime_invalid_input():
+    assert scalars.serialize_datetime("test") is None