Rainboe - I agree.
I've long since forgotten the formula, but Rate 1 turns are not a concept used in heavy jet aircraft, and I believe that a 25 degree angle of bank turn will give you (in still air) less than Rate 1 (by how much I can't remember and don't care either!).
I do remember in practice (when I was flying aircraft without an FMC and auto hold pattern tracking), that I would start the stopwatch abeam the holding fix and fly an adjusted outbound heading for 1 minute +/- a wind adjustment before turning inbound, this would result in the inbound time being whatever it took to reach the fix. The total hold is usually about 5 minutes in a medium or large transport jet.