I've been wearing my current contacts for 8 months 24/7 without ever taking them out.
Ive had mine in for close to 4 years no (24-7) ... I can tell my prescription has changed .... But otherwise haven't had any issues.
For soft, I have heard a few days, but if irritation occurs remove or you may have to have this done by an optometrist. Better to remove everyday as it is better to be safe than sorry
Okay, now I don't feel bad for wearing mine for so long! Lol
I have worn the same pair of Air Optix Night and Day contacts non-stop (24x7, even sleep in them) for 2 months or more. When my eyes bother me I take them out for two days and put in the next pair. I can go a whole year on two boxes of contacts per eye.