Wow, I really was expecting a serious issue when reading the title of this thread... but it is in my opinion clearly not.

First of all, not being able to check in online early doesn't discriminate, as it has no real advantage (others wrote that you can select your sear in advance).

Secondly, it is rather probable that ElAl can't check you in more than 24 hours in advance, because CKI for your flight is simply not open at that time. The reason for the 24h-period is that many airlines can handle only one flight with the same flight number at a time.