login problem

Hello, so yesterday I was doing exam tasks, which consisted in setting the days and hours in which the user can log in, unfortunately because I entered the wrong command the first time and in the administrator account by mistake, then I did so until 2 account and checked if the expected result came out, it turned out that at the login time point was "missing", so I did not change anything and turned off the computer and since then I can not log in to the accounts. My question is, is it fixable? Thank you in advance for your help.