I found an error on the linked page, but unfortunately the author doesn't appear to have contact information anywhere, so I can't really report it. :(

That page (in 'The Details') reports that the length of a year will change over time due to leap seconds, but that's not actually the case -- leap seconds correct for changes in the Earth's rotation on its axis, but years measure the Earth's trip around the sun, and these two things are unrelated.

(Leaving here on the extremely off chance the author of that page reads HN!)