Once companies start making layoffs, how long does it take them to usually stop firing people?

I've been looking for a job since mid October, and I just landed a job offer from a top tech firm (excluding FAANG). I've just read an article that they're planning to layoff 20% of their workforce. <br><br>How long does it usually take for a company to already stop firing people? Do you think a full 20% is a one day affair?