I disagree. Time does not affect the quality of a node...whether the quality is good or bad. I think that a node will deserve what it deserves no matter when it is viewed and voted upon. While, this idea could prevent some abuse, I think that it would be a shame to have a limit on the time that you can reap the fruit (XP) of your labors (nodes). (And by the same token, if your fruit (nodes) are rotten, you should bear the consequences (anti-XP.)