Even with spurs age is tough to judge. Harsh terrain does wear on pointed tips.

But what I have seen - a bump both sides for a spur measuring up to 7/8" inch more than likely a 2 yr old.

Spurs over an inch and sharp to a point 3 yrs and hooked and really sharp could be 4 yrs.

That is for Easterns from what I have witnessed.

JW