There are cultures where you just close up shop when you've had enough income for the day. Not to mention rural communities all around the world that are more flexible about timekeeping in general.
I'd say all the services which require face to face interaction will become way more costly if such buffers will be needed to cover off hours. For example: there is a notion of skeleton crew and the service might not be operational without that crew so the choice is actually to spread the cost of off hours low load to the high load hours or close the business for low load hours.
If there is a will, a structure for all work can surely be created where even more intermediation happens and productive artifacts are exchanged rather than physical presence. This applies much more broadly than so-called "knowledge work", it just happened first for knowledge work because it's most obvious and low-cost there.