A client in the restaurant industry asked me a few weeks ago: "Am I required to record the clock-ins and clock-outs of my waiters, or is that something I do if I want to?". The answer caught him off guard: it is not optional. Argentine regulations have required employers to keep a record of working hours since 1929, and those who don't pay dearly the day a lawsuit arrives. Here I explain exactly what the law requires regarding attendance control, which regulation mandates it, and why keeping the record up to date is the cheapest thing you will do for your company.