My emacs org-mode agenda files are steadily growing, and many of my projects span several to many years. In addition, I need to last access the entries after about a year. Hence rather than (or in addition to) archiving my agenda entries per project, I would like to archive all my agenda entries from a given date range, for example (half) a calendar year. Is this possible somehow? Since I need to do this once or twice a year, it isn't too bad if I need more than a few keystrokes for this action (which I could stick in a macro anyway). Even if the solution would only work for a given month or calendar year, rather than any random date range, it would help me.
My work agenda file has a structure like below. I would like that structure to be kept in the archive file, in case I ever need to figure out how much time I spent on a given project or on all my teaching years later.
* Research ** Project 1 ** Project 2 ** Project N * Teaching ** Class 1 ** Class 2