I can't find much documentation past defining what this is supposed to do in terms of fetching reported results from the last 24 hour time period.

--get_old_tasks show reported tasks from last 24 hours

But in my case, I seem to only be fetching the last few hours worth, nowhere near 24.
Is there better documentation that may explain this?

-- versions --

boinccmd --version
boinccmd, built from BOINC 7.6.33
boinccmd --client_version
Client version: 7.6.33

According to the rpc documentation it's only an hour...

get_old_results(vector<OLD_RESULT>)
Get a list of results that have been completed in the last hour and have been reported to their project. (These results are not returned by get_results()).

I had boinccmd tell me 24 hours and having it actually only be 1 hour?

Yes, there are other places from the worker's filesystem where the data I'm after resides, but I'm working with the XML RPC that things like the boincmgr and boinccmd use. The documentation for this particular feature seems to be at odds with it's actual functionality, and I am trying to figure out what the actual specifics are.

--get_old_tasks operates by doing a GUI RPC against the currently-running client. I haven't traced it any further back than that, but I'd assume for the time being that it is retrieving results from the memory space maintained by the current BOINC client instance: in other words, only since the beginning of the current session.

I'll come back and let you know if I find out any more.

Edit: commit dd7c8335f3a0f743679c61610d5a3946cb454c30 supports that interpretation:

Client: keep an in-memory list of reported tasks in the last 24 hours, and add a GUI RPC for fetching this list.

Edit 2: Hmmm. Checking it out on the (old, slow) laptop in front of me, which has been running continuously since 17 November, I find 26 completed tasks reported in the message logs for the last 24 hours. But only two of them - both reported in the last four hours - appear in response to a --get_old_tasks. Back to the drawing board.

I would say that it's not a problem with boinccmd but perhaps with boinc-client, going straight into the GUI RPC with <get_old_results/> gives the same inaccurate results as is provided by boinccmd with --get_old_tasks

I'd agree with that. I've tried with one of my faster machines: in the last 24 hours, it's completed 317 tasks, but --get_old_tasks only reports the final 16 of them (about [edit] 1 hour.

Another problem with --get_old_tasks: for the few tasks it does find, it reports separately on "completed time" and "reported time", but the values are identical. I'm using <sched_op_debug> logging, so I get a timestamp for "got ack for task" every time. It doesn't match "reported time".

Edit: found 9024f8cc18fe06b4c9d8bededda80355e4aaceb6:

Client: change length of old-results log from 24 hours to 1 hour

I'll update the documentation.

Boinccmd manual updated.

Reported to developers as #2268

Great! Thanks for the confirmation and the assist.

My last thought on the matter for the moment is that it would be handy if it used a sequence id like with messages and notices so that superfluous fetching of old_tasks can be eliminated.