Currently, I am trying to change my date column that is stored as a character type into a date type. I am successfully able to use lubridate to make this change. However, it eliminates my data frame and only keeps the new dates as values.
How can I keep everything contained in the data frame?
You are overwriting your entire data frame with the value for the newly created date column.
Instead do
dc.crime.complete$Date <- ymd(dc.crime.complete$Date)
This will overwrite your date column with the new values.