When you try to set a NA with case_when for a date column, you might get below error
case_when(country == “Argentina” ~ today(), TRUE ~ NA)
Error : must be a `Date` object, not a logical vector Call `rlang::last_error()` to see a backtrace
To address the issue, you can try
TRUE ~ as.Date(NA) instead of
TRUE ~ NA
See How to set NA for Date Column with case_when for details.