if itss between now and Christmaas you better allow at least 2 hours or more
It depends on when you re traveling. If you go during the busy holiday rush, then I d get there about two hours before your flight departs. If you go during a time that s not busy, you can allow one hour since you have no bags to check in.
Just barely enough time, 2 hours or at least 90 minutes would give you a better margin for problems. Unless, like the others say, it might be a particularly busy day, like the few days before Christmas. In that case you are just begging for trouble at 1 hr.