P, no that 21 minutes is correct for the RCI1. It’s a 60-minute workout.
5 warmup
21 Zone 2
24 intervals
5 Zone 2
5 Cooldown
= 60 minutes
We built some of the workouts to be exactly 60 minutes long no matter what, and some workouts are built around the interval exclusively and have weird durations, like 52 minutes.