I read Casio promises 30 sec/month but (lucky?) customers report losing 2 seconds per month. I know its a cheap watch but would it be that hard to have a setti

I read Casio promises 30 sec/month but (lucky?) customers report losing 2 seconds per month. I know its a cheap watch but would it be that hard to have a settings for it? I hear people tuned antique pendulum clocks to seconds per year. I suppose it helps that they are inaccurate enough to have tuning?