How to prevent write.csv from changing POSIXct, dates and times class back to character/factors?

Question

I have a .csv file with one field each for datetime, date and time. Originally they are all character fields and I have converted them accordingly. At the end of my code, if

Answer 1

According to ?write.table:

Any columns in a data frame which are lists or have a class (e.g. dates) will be converted by the appropriate 'as.character' method: such columns are unquoted by default.

Simply put, you can only write text/characters to text files. Use save if you want to preserve the binary R representation of your object(s).