consultation day; appointment day
Refers to the day of a medical consultation or examination. Commonly used in hospital or clinic contexts.
The next consultation day is next Tuesday.
I wrote down the appointment day on my calendar so I wouldn't forget.
受診日 also means 'day of medical consultation', but 受診 emphasizes the patient's act of receiving the examination, whereas 診察日 is more neutral and commonly used by medical institutions.
Compound of 診察 (shinsatsu, 'medical examination') and 日 (bi, 'day').