If you have developers making changes to production systems with live customers, the real problems at your company have little to do with when people show up for work.
I rarely roll in to work earlier than 10 am, and that is down from about 11 am at my last job since this one has a regular 10 am scrum meeting. Yet, I wouldn't consider leaving a broken build active on Friday evening, and I'm just talking about the tip build in source code control, not a broken production system. I wouldn't even consider working for a place where developers just pushed new code willy nilly to live production systems, because that's just stupid.