Can You Charge to be a Witness in a Custody Case

My question involves juvenile law in the State of: Texas

I have been subpoenaed for a deposition in a few weeks and a given date and time. This matter is a custody issue between two very rich and silly parents who have more money than sense. Deposing me is frivolous as I have virtually no knowledge of anything in this case. My wife is a friend of one of the parents. I am a physician and frequently testify as an expert witness in depositions. My question is this: can I charge for my time in testifying in this deposition? If so can I charge my standard rate of 600/hr? I have patients scheduled for the date they have chosen and it will cost me a few thousand dollars in revenue to shut my office down during the time they have chosen for the deposition.

Obviously, I am hoping to have them drop their request for me to appear since they know I literally have no knowledge that would be of any benefit to them. But if they insist, I want to be reimbursed for my time at my standard rate of 600/hr for depositions. ( 3 hour minimum). How should I proceed? Is this even possible?

If you are subpoenaed as a fact witness, you get the standard witness fee (normally small fee based on each half-day of trial you attend, plus a mileage reimbursement). If you believe that they want you to testify as an expert, but are avoiding paying your fees by calling you as a fact witness, I suggest discussing possible deposition strategies with a lawyer.

As this is a deposition, you can discuss with the lawyer for the party that subpoenaed you whether you can schedule the deposition for a time that is less disruptive to your business.