This is a bit like the clients with low rates or clients with high rates discussion. Clients who will pay high rates actually tend to be more respectful of your time and expertise.
Similarly a chargeable day is a day when you provided the contracted services period. It doesn't come with fixed hours or even a fixed amount of hours. It doesn't come with a guarantee that you won't take a quick call with someone else in the middle of the day or a two-hour lunch date. It does include travel, phone calls, answering "quick questions" on Teams or Slack or whatever they use, and anything else you do to provide the contracted services.
Anyone who doesn't like that can find someone else to work with who is willing to put up with all the other nickel and dime stuff that client will surely try. No-one I worked with on a day rate ever even questioned it. What you get done on the days you charge for will tell a client soon enough if you're providing the value they're paying for and if you are then they won't have any reason to worry about nit-picking the wording in your contract.
Similarly a chargeable day is a day when you provided the contracted services period. It doesn't come with fixed hours or even a fixed amount of hours. It doesn't come with a guarantee that you won't take a quick call with someone else in the middle of the day or a two-hour lunch date. It does include travel, phone calls, answering "quick questions" on Teams or Slack or whatever they use, and anything else you do to provide the contracted services.
Anyone who doesn't like that can find someone else to work with who is willing to put up with all the other nickel and dime stuff that client will surely try. No-one I worked with on a day rate ever even questioned it. What you get done on the days you charge for will tell a client soon enough if you're providing the value they're paying for and if you are then they won't have any reason to worry about nit-picking the wording in your contract.