Do they actually have any dairy products in? If so I'd keep them in the fridge and throw them out after 3 days or if they start to smell strange... I seem to remember making them at school though and that was without any milk/cream - if that's the case I'd have thought they'd keep for a week or so at least - they might start to dry out or discolour though.
Hi immortal,my mother makes those for my neice,but she generally has them eaten within a couple of days anyway,so they never get a chance to go off! In the fridge,i'm sure they'd be ok for a few days.Not any longer though,cos the egg white hasn't been cooked.