The phrase 'standing appointment' is correct and usable in written English.
You would typically use it when referring to a regular meeting that happens at the same time and place on a recurring basis. For example, "I have a standing appointment with the doctor every Tuesday morning."
She understood and encouraged my self-reliance and I looked forward eagerly to our standing appointment.
She has a standing appointment with Mrs. Harris every Thursday morning.
As someone who has had a standing appointment with my therapist for many years, the rhythms were familiar.
We settled on Tuesday mornings, a standing appointment etched in my calendar for more than three years.
Mr. Greenberg, like many of Mr. Vivot's customers, has a standing appointment (once every 10 days) and a credit card on file.
After what I felt was an unprofessional response to a traumatic life event, I canceled my standing appointment through the reception desk and never went back.
Meanwhile, Mom Crush and I went on second and third dates with our kids, and have now exchanged books and many e-mails, and set standing appointments to go on early-morning weekend walks without the kids.
The most motivated students have standing appointments--once a week is common--and are expected to bring along their latest writing assignments, at whatever stage of development, from studying the assignment to fine-tuning the prose.
Is this any way for the Yankees to keep that standing October appointment?
The shocker was that it was unruly; Drummond used to keep it close-cropped, and practically regimented, by a standing weekly appointment at the barbershop.
He was headed east instead, toward a long-standing appointment at the federal courthouse.
