diff --git a/example.py b/example.py
index d5d96f6..32140ae 100644
--- a/example.py
+++ b/example.py
@@ -1,4 +1,5 @@
-import datetime
+from datetime import datetime
+from datetime import timezone
 
 from covjson_pydantic.coverage import Coverage
 from covjson_pydantic.domain import Domain
@@ -10,7 +11,7 @@
         axes={
             "x": {"dataType": "float", "values": [1.23]},
             "y": {"values": [4.56]},
-            "t": {"dataType": "datetime", "values": [datetime.datetime.now()]},
+            "t": {"dataType": "datetime", "values": [datetime.now(tz=timezone.utc)]},
         },
     ),
     ranges={"temperature": NdArray(axisNames=["x", "y", "t"], shape=[1, 1, 1], values=[42.0])},
diff --git a/src/covjson_pydantic/domain.py b/src/covjson_pydantic/domain.py
index a735f0e..c59a51a 100644
--- a/src/covjson_pydantic/domain.py
+++ b/src/covjson_pydantic/domain.py
@@ -1,4 +1,3 @@
-from datetime import datetime
 from enum import Enum
 from typing import Generic
 from typing import List
@@ -8,6 +7,7 @@
 from typing import TypeVar
 from typing import Union
 
+from pydantic import AwareDatetime
 from pydantic import ConfigDict
 from pydantic import model_validator
 from pydantic import PositiveInt
@@ -61,7 +61,7 @@ class Axes(BaseModel):
     x: Optional[Union[ValuesAxis[float], CompactAxis]] = None
     y: Optional[Union[ValuesAxis[float], CompactAxis]] = None
     z: Optional[Union[ValuesAxis[float], CompactAxis]] = None
-    t: Optional[ValuesAxis[datetime]] = None
+    t: Optional[ValuesAxis[AwareDatetime]] = None
     composite: Optional[ValuesAxis[Tuple]] = None
 
     @model_validator(mode="after")