I've changed my hours once. It affected one family and they left. I was ok with that because I wanted the later morning start.

My family needed the extra hours, though. If your family doesn't *need* them, then I don't see it being a problem. I don't think the reason why you want to change them matters.... to the family. I just worded it that I needed to change the hours of my business to better suit my business' and family's needs, therefore my new hours are ..... effective ..... I gave lots of notice, though. Two months worth. And she stayed up until the new change of hours.

Good luck!