semster 2 exam timetables

hi! i am an exchange student studying at nuig for the semester. ik exam timetables are coming out next week and i am a bit confused about how the system works. my main question is: how likely are timetable amendments? im planning on scheduling my flight home based on my timetable and i dont want to book something when initial timetables come out and then have to last minute change because of an amendment.