Different Dates

Date of ACQUISITION is date I added a mp3 to my collection.

%_file_mod_datetime% etc. are inappropriate placeholders because they changes with changing a tag.

%_file_create_date% and its variants seem to be appropriate, however:

  • unclear to me: what is %_file_create_date%, where it comes from?
  • Sorting on %_file_create_date% doesn't work propper with me, while sorting on %_file_mod_datetime% works as required. Why?

Thank you in advance for an answer.

The file dates are (usually) set by the OS and are properties of the file and not a atg. You can see that this a pseudo tag as it starts with an underscore.
For the sorting check if the date-column has got ticked "numeric" (the working probably has, the other one probably hasn't).
If you want to log the date when you got the file in your library then you probably have to create a user-defined tag.