Manual files of unix programs are written in a really dry, precise style, which I find a bit intimidating at times. Feels as if they were written by objective computers, not mere subjective mortals.
Then again, crontab's manual has some pretty dubious stuff (see image): The list itself is 1-indexed; minute, hour and day of week are 0-indexed, and day of month and month of year are again 1-indexed.