How to say "almost exactly 1 hour"?

How to say "almost exactly 1 hour"?

In my impression, there is one word means the time is almost exactly, like
"almost exactly 1 hour".
It is less precise than exactly. (Is "punctually one hour" a right term?)
But more accurate than about 1 hour. (How to say "about one hour"?
1-hour-ish?)