Defraggler "Health Screen"

I have a question about the POH. I am seeing that it reads about 778- days. That amounts to about 18,600 hours. I am running a laptop personal computer with Windows Vista. My question is- could that be the actual time that the computer has been turned on & is there any other way I could find that data somewhere else on my computer to verify this is correct? I mean to say, is it stored locally on my computer & how would I find this info?

The data in the health section is S.M.A.R.T information that is provided directly by the hard drive

https://en.wikipedia.org/wiki/S.M.A.R.T