It's interesting, but some of the earliest accounting software I used, which was COBOL-based, didn't allow you to change any ledger once a month was posted and closed. I suppose it was possible to go into the actual database and directly alter records, but the underlying concept was that once a fiscal period was complete, it was inviolate, and the only way you could alter any closed ledger was to post adjusting entries in this period. This could be rather ugly, so you tried really hard not to do any major mistakes. Even end of the year adjusting entries were posted in the next fiscal year.
Since then I've seen a number of accounting systems that allow all sorts of monkeying around, including posting adjusting entries for a fiscal year within that fiscal year, even though you may be a couple of months into the current fiscal year. It seems common practice now, but a quarter of a century ago that was viewed as completely inappropriate, as it opened the door for fraud.