Looking on the internet deeply has found these results:

attend to an appointment is the most popular phrase on the web.

attend an appointment 1329,000 results on the web	attend to an appointment 1999,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I just remembered I have an appointment next week. I called your therapist and made an appointment. If you forget to attend an appointment: Before taking up his duties, a Judge or Advocate General shall, at the first public sitting of the Court which he attends after his appointment, take the following oath provided for in Article 2 of the Statute: Can you attend an appointment tomorrow? Call the secretary for an appointment. I was in Thailand to attend an investment conference. He canceled the appointment to attend the meeting.	I have an appointment with Mr o'clock. Call the secretary for an appointment. I called your therapist and made an appointment. He canceled the appointment to attend the meeting. If you forget to attend an appointment: I just remembered I have an appointment next week. Before taking up his duties, a Judge or Advocate General shall, at the first public sitting of the Court which he attends after his appointment, take the following oath provided for in Article 2 of the Statute: Can you attend an appointment tomorrow?

attend an appointment

1329,000 results on the web

attend to an appointment

1999,000 results on the web

More popular!

I just remembered I have an appointment next week.
I called your therapist and made an appointment.
If you forget to attend an appointment:
Before taking up his duties, a Judge or Advocate General shall, at the first public sitting of the Court which he attends after his appointment, take the following oath provided for in Article 2 of the Statute:
Can you attend an appointment tomorrow?
Call the secretary for an appointment.
I was in Thailand to attend an investment conference.
He canceled the appointment to attend the meeting.

I have an appointment with Mr o'clock.
Call the secretary for an appointment.
I called your therapist and made an appointment.
He canceled the appointment to attend the meeting.
If you forget to attend an appointment:
I just remembered I have an appointment next week.
Before taking up his duties, a Judge or Advocate General shall, at the first public sitting of the Court which he attends after his appointment, take the following oath provided for in Article 2 of the Statute:
Can you attend an appointment tomorrow?