I was given guidance on the waiting time at the Suwon ENT Clinic.

I visited because my throat hurt when I swallowed. Because it was flu season, there were usually a lot of patients waiting. The wait was long, but the doctor thoroughly examined me when it was my turn, so the wait was worth it. He checked to see if I was taking any medications for other conditions and gave me detailed instructions on how to take them to avoid any overlap.
The nurse at check-in was very kind and gave me guidance and told me the approximate wait time, which I was told was pretty close to my appointment time. Since she told me the expected wait time, I didn't have to ask when I could be seen, so I was able to wait relatively comfortably. This is a hospital in my area where you can participate in the lottery.