Sorry, with this "don't apply on the day applications start/too early" I assume that means don't submit the application early, rather than starting to fill in the online application (but not submitting it) early?
One final question. Is it better to wait until the start of the university term, when I'm registered etc) to apply, or is it acceptable to apply with an unconditional offer but not actually at the university yet? This is for a spring internship.
For spring internships they won't even bother until they sort out summer. I applied in Nov. which is when the eager ppl start to apply it's still way to early for that.