code: def test_update_df_date_timestamp(self, util):
      tbl = Table({"a": [date(2019, 7, 11)]})
  
      assert tbl.schema() == {"a": date}
  
      update_data = pd.DataFrame(
          {"a": [util.to_timestamp(datetime(2019, 7, 12, 0, 0, 0))]}
      )
  
      tbl.update(update_data)
      assert tbl.view().to_dict() == {
          "a": [datetime(2019, 7, 11), datetime(2019, 7, 12)]
      }
  
imports: import numpy
  import pandas
  from datetime import date, datetime
  from pytest import mark
  from perspective.table import Table
label_desc: Use image node_id 6 for calling the TestUpdatePandas obj's underlying member method code with example usage: obj.test_update_df_date_timestamp(util) without return types