In an absolute sense: you don’t. Surprising as it might seem, that kind of information actually doesn’t exist. There’s no place, no standard, no way to absolutely, positively say that this web page was written on this or that date.
The date that much of the information on the internet was written often doesn’t factor in to its value. But there are also times when knowing whether a page is a month, a year or a decade old can have a dramatic impact on its relevance.
While not absolute, and not 100% reliable, there are often clues we can use to determine just how old a page might be.
Let’s look at what some of those are.