diff --git a/src/py_avro_schema/_schemas.py b/src/py_avro_schema/_schemas.py
index 41d5663..2565fff 100644
--- a/src/py_avro_schema/_schemas.py
+++ b/src/py_avro_schema/_schemas.py
@@ -351,7 +351,7 @@ def data(self, names: NamesType) -> JSONObj:
 
     def make_default(self, py_default: datetime.date) -> int:
         """Return an Avro schema compliant default value for a given Python value"""
-        return (py_default - datetime.date.fromtimestamp(0)).days
+        return (py_default - datetime.date(1970, 1, 1)).days
 
 
 class TimeSchema(Schema):