for further clarification, by default, the timetable on myunsw displays your classes across the entire term, i.e. it ticks every week from 1 to 11 up in the top left. i recall with ENGG1000 that the monday lecture alternated weekly between 2-4pm and 2-5pm, but by having all the weeks ticked, you'll see both of them occupy the same slot. If you only tick one week, you'll see there's no clash.