Between clinical interview and ADOS - how long did you wait?

I'm struggling to understand why I'm having to wait to hear from my clinic to get an appointment date for my ADOS test. Surely they simply need to identify a date and time when the clinicians and a room are available, block the time off in the calendar and send me an email or letter or phone me? Why does that take a long time? They don't have to hire a clinician, build a new room, buy in equipment........

I understand that the date of the ADOS itself could be some weeks or months in the future, but why am I having to wait weeks to simply get a date? They've told me that they don't do ADOS "all the time" so I don't think there is a queue of people who have to be processed first.

How long did you have to wait?