This is the 2159th most frequent Korean word.
일정이
"일정이" means "schedule is" or "schedule" (subject/topic marker).
In this sentence, '일정이' (iljeongi) is being used as the subject to indicate a person's schedule.
오늘은 일정이 바빠서 점심을 못 먹을 것 같아요.
Today, I think I might not be able to eat lunch because of a busy schedule.
Here, '일정이' refers to planned activities or appointments, used in an honorific manner to inquire about someone's plans.
내일 아침에 일정이 있으신가요?
Do you have any plans tomorrow morning?
In this context, '일정이' specifies the schedule that has been altered due to a change in plans.