Dale,
Sorry for misspeaking (no intention of lying), I just forgot to finish the statement of "30 days to have 10 practices".
But... I remember those "10 non-contact days". We put in a massive part of the offense in those ten days. Instead of trying to learn the offence in preseason, we already knew most of it by the time practice officially opened in the fall.
Imagine if you will a "fall window" for spring sports.
You could put in all of your set pieces, as well as "shadow play" to learn your offensive and defensive system of play. You could also do all sorts of footwork, passing, receiving, etc. What a huge difference that would make, wouldn't it???