when I run this code, my df in the environment panel appeared as Tibble(check screenshots). It happened because it is quite a large dataset or? there are more than 3mln rows.
and when I press the play button in the environment panel it does not show me columns and data types anymore.
This likely happens due to how the apr_2020 and other objects were imported. If readr::read_csv() was used, the default is a tibble. A tibble is just a data frame in party attire and a data frame is just a matrix that allows mixing character and numeric types. Unless using numeric datetimes (seconds from The Dawn of Unix), you will need a data frame, tibble or data.table to accommodate the date objects.