Issue #13727: Add 3 macros to access PyDateTime_Delta members:
PyDateTime_DELTA_GET_DAYS, PyDateTime_DELTA_GET_SECONDS,
PyDateTime_DELTA_GET_MICROSECONDS.

Please use them instead of directly accessing PyDateTime_Delta struct members.
diff --git a/Include/datetime.h b/Include/datetime.h
index db57a18..41e3bcf 100644
--- a/Include/datetime.h
+++ b/Include/datetime.h
@@ -135,6 +135,12 @@
      (((PyDateTime_Time*)o)->data[4] << 8)  |           \
       ((PyDateTime_Time*)o)->data[5])
 
+/* Apply for time delta instances */
+#define PyDateTime_DELTA_GET_DAYS(o)         (((PyDateTime_Delta*)o)->days)
+#define PyDateTime_DELTA_GET_SECONDS(o)      (((PyDateTime_Delta*)o)->seconds)
+#define PyDateTime_DELTA_GET_MICROSECONDS(o)            \
+    (((PyDateTime_Delta*)o)->microseconds)
+
 
 /* Define structure for C API. */
 typedef struct {