This is honestly over complicating things.
People do not care wether you are a day or two late, early, or even longer.
Just make sure each day is as profitable as it can be, and work each day you want to. When you go on holiday, pick up where you left off.
I work on a “monthly” schedule, but I tell everyone it’s roughly 4-6 weeks depending on holidays, stormy weather etc.
People DO NOT care. They are just happy I’m regular.
Don’t put yourself under pressure. Window cleaning should be the opposite.