FILE: .emacs
(setq org-archive-location (concat "~/Documents/Reference/org/archive/" (format-time-string "%Y-%m") ".org::"))

FILE: main2.org
* Done item

FILE: *Messages*
Subtree archived in file: ~/Documents/Reference/org/archive/2019-06.org

FILE: 2019-06.org
Archived entries from file /Users/janmeppe/Documents/Reference/org/main2.org


* Done item
:PROPERTIES:
:ARCHIVE_TIME: 2019-06-18 Tue 11:26
:ARCHIVE_FILE: ~/Documents/Reference/org/main2.org
:ARCHIVE_CATEGORY: main2
:END:

(advice-add 'org-archive-location :after #'org-save-all-org-buffers)