Most USCIS Field Offices do not make both interview and oath ceremony at the same day for an individual applicant because the oath ceremony is very serious and the immigration judge needs to attend. So, many applicants who passed the interview normally take the oath at the same time. But sometimes if the Field Office has set up the ceremony for other applicants and your interview appointment is also made at the same day coincidentally as the oath ceremony, then you will be required to take both the interview and oath at the same day.
Of course, you can request reschedule the oath ceremony with the convincing reason.
