Is it's true on senior day to get half off on the buffet you must get a certain amount of points on your card

Yes it's yrue

Right it's only 20 points not 100. 20 points for seniors 55 and older. The 100 points is for $10 in Jena Cash

Yes yiu get half off when yiu het a 100 points on your card

I have to reach 20 points to get half off.

I think so. It use to not be that way though.