I like to start as early as possible. 7am is good, but 8am will do. If it's an empty interior I'll start at 6am. I think it creates a small problem when they want you to start at 9am - 10am everyday (there are exceptions). Especially when it's an exterior. Workers are used to a schedule & arrange their lives around that schedule. When you need to change your morning around 2 hours, your evening around 2 hours, then go home with no time to get your responsibilities done, it can become a small problem with the workers. When we're there for 2 weeks and every day is a different start time, 10am one day, 8am the next, 11am the next, 9am the next, and for no reason other than that's the time that pops in her head for wanting to answer the door, it should be explained to them the needs of the company to get the job done in a costly timely manner.