How late can you do construction in Los Angeles?

I just bought a rental property in a nice area and I have been refurbishing it. Mostly painting and small repair but now I am refinishing the hardwood floors. I am sanding floors and my neighbor is tripping out. I am using rented sanders and it was only 7:00pm. They aren't that loud (you can barely hear them from outside) and I told her I would be finished at 10:00pm. She said you can't do it after 7pm. So who's right? The machines are expensive to rent and the work has to be finished. I don't want a problem but I feel that it is important to finish so we can stain and do the base boards tomorrow.