coerce parsed datetime to ns resolution

Author: cmeeren

pandas/io/parsers.py

@@ -2154,7 +2154,7 @@ def _try_convert_dates(parser, colspec, data_dict, columns):
     new_name = '_'.join([str(x) for x in colnames])
     to_parse = [data_dict[c] for c in colnames if c in data_dict]
 
-    new_col = parser(*to_parse)
+    new_col = parser(*to_parse).astype('datetime64[ns]')
     return new_name, new_col, colnames