Sorry, they SAY that is how old it is but they are lying. How do they date it? By the core rings that they ASSUME are annual. They do not represent years, they represent periods of warming and cooling, i.e. hot days, cold days etc.
Don't be fooled by their fake interpretations. Might as well toss this in there too. As far as radiometric dating goes, it's all bogus as well. Dates are based on pure assumption. They ASSUME initial saturation levels of whatever they are measuring and then assume a constant rate of decay and they assume that the rate of decay is the same as we experience today. They have NO CLUE of what the initial saturation levels were, no clue of whether the rate of decay was the same as today and they have no clue of whether it decayed at a steady rate. They just assume all those factors. The truth is, they play with the numbers until they get the results they want and toss out the results they don't want. They want you to believe in evolution, which could never actually happen. They are atheistic haters of God and the creation. I know that is going to chap some hides but it's the truth nonetheless.