nightly window cleaner

A guy who comes to your house every night to clean your windows while you sleep. He will only come if you sleep at any point of time in the night, and if you pull an all-nighter then your windows will not be cleaned. This could be an issue under circumstances where your window has the potential to get very dirty. There is a common saying, "Get a full night's rest, or your windows will be dirty!" which I did not just invent on the spot for the convenience of this definition.

"I've pulled two all-nighters in a row and I'm so tired!"
"Your windows must be dirty, maybe you should sleep to the nightly window cleaner will come?"
"That's a good idea."