That would be covered under formal social occasions where formalwear is mandatory.
The situation above is also a bit odd as most employers IME would be very understanding enough to encourage the employee to take at least the entire day off or sometimes more if needed.
After finding I got the job in an IS department of a mid-sized Boston area financial firm, my interviewer and later supervisor said while he understood why I wore a suit and tie to the interview to wear business casual in the future for the same reason.