The pseudo tag field content %_file_mod_datetime_raw% provides an integer number, which can be used within a scripting function expression or a filter expression, where a number is expected.
Examples:
"%_file_mod_datetime_raw%" GREATER 1274175303
"$ifgreater(%_file_mod_datetime_raw%,1274175303,1,0)" IS 1
Tip for practical usage:
Create and display two new columns in Mp3tag list view.
1.
Name: File Mod DT
Value: %_file_mod_datetime%
2.
Name: File Mod DT Raw
Value: %_file_mod_datetime_raw%
Field: %dummy%
Numeric: on
Although the info fields are read only, the dummy field let you copy the number value from the list view cell onto the clipboard. Then paste the clipboard content into the filter expression.
Without any filtering it may helpful to sort the list view by column "File Mod DT", ascending or descending, to get a practical overview.
DD.20100822.1615.CEST