Split up date yyyymm into two columns

Hi Andreas,

I'm not sure what your end goal is of splitting this into two columns, but assuming that your mdate column is already of class Date, it should suffice to only use the last two lines of your code.

The format() function is intended for pretty printing and, for this specific purpose, requires a date object.

If this is not helping you further, can you please provide a reprex (reproducible example) so that we can assist you better?