diff --git a/README.md b/README.md
index 9760759..0576f53 100644
--- a/README.md
+++ b/README.md
@@ -389,6 +389,26 @@ params = (
 regions = client.regions().list(params).data
 ```
 
+## Date and Datetime Fields
+
+The SDK distinguishes between date-only and datetime fields:
+
+- **Datetime fields** are deserialized as `datetime.datetime` with `timezone.utc`:
+  - All `created_at` fields — present on most resources
+  - Expiry fields: `Did.expires_at`, `DidReservation.expire_at`, `Proof.expires_at`, `EncryptedFile.expire_at`
+- **Date-only fields** (`Identity.birth_date`, `CapacityPool.renew_date`, `DidOrderItem.billed_from`/`billed_to`) remain as `string` in `"YYYY-MM-DD"` format.
+
+```python
+from datetime import timezone
+
+did = client.dids().find("uuid").data
+print(did.created_at)   # datetime(2024, 1, 15, 10, 0, 0, tzinfo=timezone.utc)
+print(did.expires_at)   # None or datetime(...)
+
+identity = client.identities().find("uuid").data
+print(identity.birth_date)  # "1990-05-20"
+```
+
 ## Enums
 
 The SDK provides enum classes aligned with the Java SDK (for example `CallbackMethod`, `IdentityType`, `OrderStatus`, `ExportType`, `CliFormat`, `OnCliMismatchAction`, `MediaEncryptionMode`, `TransportProtocol`, `Codec`, and more).
diff --git a/src/didww/resources/address.py b/src/didww/resources/address.py
index e13ce1d..23589df 100644
--- a/src/didww/resources/address.py
+++ b/src/didww/resources/address.py
@@ -1,4 +1,4 @@
-from didww.resources.base import DidwwApiModel, SafeAttributeField, RelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, RelationField, Repository
 
 
 class Address(DidwwApiModel):
@@ -8,7 +8,7 @@ class Address(DidwwApiModel):
     postal_code = SafeAttributeField("postal_code")
     address = SafeAttributeField("address")
     description = SafeAttributeField("description")
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
     verified = SafeAttributeField("verified")
 
     country = RelationField("country")
diff --git a/src/didww/resources/address_verification.py b/src/didww/resources/address_verification.py
index 96fea9f..18fa15f 100644
--- a/src/didww/resources/address_verification.py
+++ b/src/didww/resources/address_verification.py
@@ -1,5 +1,5 @@
 from didww.enums import AddressVerificationStatus, CallbackMethod
-from didww.resources.base import DidwwApiModel, SafeAttributeField, EnumAttributeField, RelationField, CreateOnlyRepository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, EnumAttributeField, RelationField, CreateOnlyRepository
 
 
 class _SplitSemicolonField(SafeAttributeField):
@@ -21,7 +21,7 @@ class AddressVerification(DidwwApiModel):
     service_description = SafeAttributeField("service_description")
     reject_reasons = _SplitSemicolonField("reject_reasons")
     reference = SafeAttributeField("reference")
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
 
     address = RelationField("address")
     dids = RelationField("dids")
diff --git a/src/didww/resources/base.py b/src/didww/resources/base.py
index 7546d69..8e91e90 100644
--- a/src/didww/resources/base.py
+++ b/src/didww/resources/base.py
@@ -1,5 +1,6 @@
 import functools
 import importlib
+from datetime import datetime, timezone
 from enum import Enum
 
 from jsonapi_requests.orm.api import OrmApi
@@ -80,6 +81,24 @@ def __set__(self, instance, value):
         instance.attributes[self.source] = value
 
 
+class DatetimeAttributeField(SafeAttributeField):
+    """AttributeField that parses ISO 8601 datetime strings to datetime objects.
+
+    No custom setter is defined because all current datetime fields are read-only
+    (e.g. created_at). The inherited setter stores values as-is. If a writable
+    datetime field is added in the future, a setter that converts datetime back
+    to an ISO 8601 string should be implemented here.
+    """
+
+    def __get__(self, instance, type=None):
+        raw = super().__get__(instance, type)
+        if instance is None:
+            return self
+        if raw is None:
+            return None
+        return datetime.fromisoformat(raw.replace("Z", "+00:00"))  # "Z" not supported by fromisoformat before Python 3.11
+
+
 class EnumAttributeField(SafeAttributeField):
     """AttributeField that serializes/deserializes Enum values."""
 
diff --git a/src/didww/resources/did.py b/src/didww/resources/did.py
index b9d18cf..93b5d60 100644
--- a/src/didww/resources/did.py
+++ b/src/didww/resources/did.py
@@ -1,4 +1,4 @@
-from didww.resources.base import DidwwApiModel, SafeAttributeField, RelationField, ExclusiveRelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, RelationField, ExclusiveRelationField, Repository
 
 class Did(DidwwApiModel):
     _writable_attrs = {
@@ -12,8 +12,8 @@ class Did(DidwwApiModel):
     description = SafeAttributeField("description")
     terminated = SafeAttributeField("terminated")
     awaiting_registration = SafeAttributeField("awaiting_registration")
-    created_at = SafeAttributeField("created_at")
-    expires_at = SafeAttributeField("expires_at")
+    created_at = DatetimeAttributeField("created_at")
+    expires_at = DatetimeAttributeField("expires_at")
     channels_included_count = SafeAttributeField("channels_included_count")
     billing_cycles_count = SafeAttributeField("billing_cycles_count")
     dedicated_channels_count = SafeAttributeField("dedicated_channels_count")
diff --git a/src/didww/resources/did_reservation.py b/src/didww/resources/did_reservation.py
index c3ff12e..3a127d5 100644
--- a/src/didww/resources/did_reservation.py
+++ b/src/didww/resources/did_reservation.py
@@ -1,12 +1,12 @@
 from didww.exceptions import DidwwApiError
-from didww.resources.base import DidwwApiModel, SafeAttributeField, RelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, RelationField, Repository
 
 
 class DidReservation(DidwwApiModel):
     _writable_attrs = {"description"}
 
-    expire_at = SafeAttributeField("expire_at")
-    created_at = SafeAttributeField("created_at")
+    expire_at = DatetimeAttributeField("expire_at")
+    created_at = DatetimeAttributeField("created_at")
     description = SafeAttributeField("description")
 
     available_did = RelationField("available_did")
diff --git a/src/didww/resources/encrypted_file.py b/src/didww/resources/encrypted_file.py
index 0ae79a0..f274eee 100644
--- a/src/didww/resources/encrypted_file.py
+++ b/src/didww/resources/encrypted_file.py
@@ -1,9 +1,9 @@
-from didww.resources.base import DidwwApiModel, SafeAttributeField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, Repository
 
 
 class EncryptedFile(DidwwApiModel):
     description = SafeAttributeField("description")
-    expire_at = SafeAttributeField("expire_at")
+    expire_at = DatetimeAttributeField("expire_at")
 
     class Meta:
         type = "encrypted_files"
diff --git a/src/didww/resources/export.py b/src/didww/resources/export.py
index 4e35732..2bb380f 100644
--- a/src/didww/resources/export.py
+++ b/src/didww/resources/export.py
@@ -1,12 +1,12 @@
 from didww.enums import ExportStatus, ExportType, CallbackMethod
-from didww.resources.base import DidwwApiModel, SafeAttributeField, EnumAttributeField, CreateOnlyRepository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, EnumAttributeField, CreateOnlyRepository
 
 
 class Export(DidwwApiModel):
     _writable_attrs = {"filters", "export_type", "callback_url", "callback_method"}
 
     status = EnumAttributeField("status", ExportStatus)
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
     url = SafeAttributeField("url")
     callback_url = SafeAttributeField("callback_url")
     callback_method = EnumAttributeField("callback_method", CallbackMethod)
diff --git a/src/didww/resources/identity.py b/src/didww/resources/identity.py
index 50b53ac..5dcf031 100644
--- a/src/didww/resources/identity.py
+++ b/src/didww/resources/identity.py
@@ -1,5 +1,5 @@
 from didww.enums import IdentityType
-from didww.resources.base import DidwwApiModel, SafeAttributeField, EnumAttributeField, RelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, EnumAttributeField, RelationField, Repository
 
 
 class Identity(DidwwApiModel):
@@ -22,7 +22,7 @@ class Identity(DidwwApiModel):
     identity_type = EnumAttributeField("identity_type", IdentityType)
     contact_email = SafeAttributeField("contact_email")
     external_reference_id = SafeAttributeField("external_reference_id")
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
     verified = SafeAttributeField("verified")
 
     country = RelationField("country")
diff --git a/src/didww/resources/order.py b/src/didww/resources/order.py
index dbbec9f..6156f4e 100644
--- a/src/didww/resources/order.py
+++ b/src/didww/resources/order.py
@@ -1,5 +1,5 @@
 from didww.enums import CallbackMethod, OrderStatus
-from didww.resources.base import DidwwApiModel, SafeAttributeField, EnumAttributeField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, EnumAttributeField, Repository
 from didww.resources.order_item.base import OrderItem
 
 # Import to register types
@@ -15,7 +15,7 @@ class Order(DidwwApiModel):
 
     amount = SafeAttributeField("amount")
     status = EnumAttributeField("status", OrderStatus)
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
     description = SafeAttributeField("description")
     reference = SafeAttributeField("reference")
     callback_url = SafeAttributeField("callback_url")
diff --git a/src/didww/resources/permanent_supporting_document.py b/src/didww/resources/permanent_supporting_document.py
index c0b380e..4796b23 100644
--- a/src/didww/resources/permanent_supporting_document.py
+++ b/src/didww/resources/permanent_supporting_document.py
@@ -1,10 +1,10 @@
-from didww.resources.base import DidwwApiModel, SafeAttributeField, RelationField, CreateOnlyRepository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, RelationField, CreateOnlyRepository
 
 
 class PermanentSupportingDocument(DidwwApiModel):
     _writable_attrs = set()
 
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
 
     identity = RelationField("identity")
     template = RelationField("template")
diff --git a/src/didww/resources/proof.py b/src/didww/resources/proof.py
index 9e46643..247c189 100644
--- a/src/didww/resources/proof.py
+++ b/src/didww/resources/proof.py
@@ -1,11 +1,11 @@
-from didww.resources.base import DidwwApiModel, SafeAttributeField, RelationField, CreateOnlyRepository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, RelationField, CreateOnlyRepository
 
 
 class Proof(DidwwApiModel):
     _writable_attrs = set()
 
-    created_at = SafeAttributeField("created_at")
-    expires_at = SafeAttributeField("expires_at")
+    created_at = DatetimeAttributeField("created_at")
+    expires_at = DatetimeAttributeField("expires_at")
 
     proof_type = RelationField("proof_type")
     entity = RelationField("entity")
diff --git a/src/didww/resources/shared_capacity_group.py b/src/didww/resources/shared_capacity_group.py
index 3fefc46..0f2e823 100644
--- a/src/didww/resources/shared_capacity_group.py
+++ b/src/didww/resources/shared_capacity_group.py
@@ -1,4 +1,4 @@
-from didww.resources.base import DidwwApiModel, SafeAttributeField, RelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, RelationField, Repository
 
 
 class SharedCapacityGroup(DidwwApiModel):
@@ -7,7 +7,7 @@ class SharedCapacityGroup(DidwwApiModel):
     name = SafeAttributeField("name")
     shared_channels_count = SafeAttributeField("shared_channels_count")
     metered_channels_count = SafeAttributeField("metered_channels_count")
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
 
     capacity_pool = RelationField("capacity_pool")
     dids = RelationField("dids")
diff --git a/src/didww/resources/voice_in_trunk.py b/src/didww/resources/voice_in_trunk.py
index debe190..9c2a6b6 100644
--- a/src/didww/resources/voice_in_trunk.py
+++ b/src/didww/resources/voice_in_trunk.py
@@ -1,5 +1,5 @@
 from didww.enums import CliFormat
-from didww.resources.base import DidwwApiModel, SafeAttributeField, EnumAttributeField, RelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, EnumAttributeField, RelationField, Repository
 from didww.resources.configuration.base import TrunkConfiguration
 
 # Import to register types
@@ -21,7 +21,7 @@ class VoiceInTrunk(DidwwApiModel):
     cli_prefix = SafeAttributeField("cli_prefix")
     description = SafeAttributeField("description")
     ringing_timeout = SafeAttributeField("ringing_timeout")
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
 
     pop = RelationField("pop")
     voice_in_trunk_group = RelationField("voice_in_trunk_group")
diff --git a/src/didww/resources/voice_in_trunk_group.py b/src/didww/resources/voice_in_trunk_group.py
index 3ed21ed..3faed54 100644
--- a/src/didww/resources/voice_in_trunk_group.py
+++ b/src/didww/resources/voice_in_trunk_group.py
@@ -1,4 +1,4 @@
-from didww.resources.base import DidwwApiModel, SafeAttributeField, RelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, RelationField, Repository
 
 
 class VoiceInTrunkGroup(DidwwApiModel):
@@ -6,7 +6,7 @@ class VoiceInTrunkGroup(DidwwApiModel):
 
     name = SafeAttributeField("name")
     capacity_limit = SafeAttributeField("capacity_limit")
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
 
     voice_in_trunks = RelationField("voice_in_trunks")
 
diff --git a/src/didww/resources/voice_out_trunk.py b/src/didww/resources/voice_out_trunk.py
index d1647d4..c58d6de 100644
--- a/src/didww/resources/voice_out_trunk.py
+++ b/src/didww/resources/voice_out_trunk.py
@@ -4,7 +4,7 @@
     OnCliMismatchAction,
     VoiceOutTrunkStatus,
 )
-from didww.resources.base import DidwwApiModel, SafeAttributeField, EnumAttributeField, RelationField, Repository
+from didww.resources.base import DidwwApiModel, DatetimeAttributeField, SafeAttributeField, EnumAttributeField, RelationField, Repository
 
 
 class VoiceOutTrunk(DidwwApiModel):
@@ -32,7 +32,7 @@ class VoiceOutTrunk(DidwwApiModel):
     callback_url = SafeAttributeField("callback_url")
     username = SafeAttributeField("username")
     password = SafeAttributeField("password")
-    created_at = SafeAttributeField("created_at")
+    created_at = DatetimeAttributeField("created_at")
 
     default_did = RelationField("default_did")
     dids = RelationField("dids")
diff --git a/tests/resources/test_address_verification.py b/tests/resources/test_address_verification.py
index 1c69757..466ac4d 100644
--- a/tests/resources/test_address_verification.py
+++ b/tests/resources/test_address_verification.py
@@ -1,3 +1,5 @@
+from datetime import datetime, timezone
+
 from tests.conftest import my_vcr
 from didww.enums import AddressVerificationStatus, CallbackMethod, IdentityType
 from didww.query_params import QueryParams
@@ -25,7 +27,7 @@ def test_find_address_verification(self, client):
         assert av.id == "c8e004b0-87ec-4987-b4fb-ee89db099f0e"
         assert av.status == AddressVerificationStatus.APPROVED
         assert av.reference == "SHB-485120"
-        assert av.created_at == "2020-09-15T06:38:12.650Z"
+        assert av.created_at == datetime(2020, 9, 15, 6, 38, 12, 650000, tzinfo=timezone.utc)
 
     @my_vcr.use_cassette("address_verifications/show_rejected.yaml")
     def test_find_rejected_address_verification(self, client):
@@ -35,7 +37,7 @@ def test_find_rejected_address_verification(self, client):
         assert av.status == AddressVerificationStatus.REJECTED
         assert av.reject_reasons == ["Address cannot be validated", "Proof of address should be not older than of 6 months"]
         assert av.reference == "ODW-879912"
-        assert av.created_at == "2020-10-28T08:29:29.960Z"
+        assert av.created_at == datetime(2020, 10, 28, 8, 29, 29, 960000, tzinfo=timezone.utc)
 
     @my_vcr.use_cassette("address_verifications/show_with_includes.yaml")
     def test_find_address_verification_with_includes(self, client):