You have been invited to attend an interview for a place studying a course in a college. Unfortunately, because of a previous appointment, you cannot come at the time they wish.
Write a letter to the admissions tutor:
explain your position
apologise and offer to come on another day or later the same day.
ask how long the interview will be and whether there will be any tests during it.
Dear Sir,
I am writing to convey my regret because of allotted time of interview for me causes a conflict with my general health checkup appointment on the same day and time. Therefore, please consider to offer me an alternative appointment. I would be grateful to attend on any later slots or even on any other following day.
Actually, nature of my part-time job requires a monthly health checkup report for hygienic reason. Thus, they not only organized a checkup on February 5th 10 AM but also, I have agreed for it based on my day-off. Because of this, I would not be able to attend the placement interview to pursue environment science course at Hammersmith University of London. Therefore, I request you to kindly consider it to reschedule my interview time to any other time on the same day, even if it is going to be late evening. Nonetheless, please do not hesitate to reschedule it on any following day. Because, I have another day-off to take.
Thanks in advance for your prompt response.
Yours faithfully,
Yusa
