Date offset is incorrect

Has this not bothered anyone so far?

Yes, this has been raised once or twice before. See for example 🐛 Dates are poorly handled Active
But no one has been bothered about it enough to contribute a patch or even comment on that issue.

D7 is quite old at this point. I would be happy to commit a patch as long as it is accompanied by test cases and takes care not to break existing sites that use this feature. But I'm not going to work on it myself.

I'm marking this as a duplicate of 🐛 Dates are poorly handled Active - please contribute in that issue.

I undertake the testing.

I can't fix the module because I can't program in PHP and I don't know how to create a Drupal module, yet.

I don't understand that it didn't bother others, since there can be many cases when it is important.
For example, if I want to hide a content 30 days after a given date, then it doesn't matter how many +/- days have passed due to the error, if that content is related to a subscription.

Workaround:

Another feature of Rules, which also includes offset, counts well. This is interesting, because I think the module takes this action from the same place, but according to them, it doesn't?

So this solves the problem, avoiding the date offset error:

Action: Calculate a value