Just received word that the website will be down until 2pm tomorrow, if this website is anything to go by:
Aer Lingus
@Libertine, you can do the tests whenever you want within 72 hours. There are 10 of them and you can take any of them at any point, you don't have to sit them all at the same time, unless, of course, you want to. I personally, don't.
However, once you've started the test, you HAVE to finish it. Failure to do so will result in the test not being counted and thus you not being eligible for recruitment with AL.
Hope this helps