Default M8[D] reso to [ms] since arrow / parquet default to ms. Parquet

does not support [s]

Author: dalejung

pandas/_libs/tslibs/dtypes.pyx

@@ -387,8 +387,8 @@ cpdef NPY_DATETIMEUNIT get_supported_reso(NPY_DATETIMEUNIT reso):
         # TODO: or raise ValueError? trying this gives unraisable errors, but
         #  "except? -1" breaks at compile-time for unknown reasons
         return NPY_DATETIMEUNIT.NPY_FR_ns
-    if reso < NPY_DATETIMEUNIT.NPY_FR_s:
-        return NPY_DATETIMEUNIT.NPY_FR_s
+    if reso < NPY_DATETIMEUNIT.NPY_FR_ms:
+        return NPY_DATETIMEUNIT.NPY_FR_ms
     elif reso > NPY_DATETIMEUNIT.NPY_FR_ns:
         return NPY_DATETIMEUNIT.NPY_FR_ns
     return reso