Saying the words 'how long', we are asking the time period. Before time began, there was no time, and thus, even if it only started 100 million years ago, then that would be, say, forever, as before that time period, that was no time. So before time began, and there was no time, then there was nothing to calculate or even literally, the length of time that existed. Time, then, has been around forever, and if time ever stops, then this statement will no longer be able to make sense.
it has been around for a long time.
a long time
a long time
A long time.
a very long time
a very long time
the same time that any people been around.
Since the beginning of time.
"The Simpsons".
Since the beginning of time.
Xbox has been around for a long time, about eight to nine years (as of 2009), but Xbox 360 has been around about, two years, maybe a little less.
Mount Everest has been around for a very long time. It is approx 60 million years old.