Making a plan 24 hours before- Urge Jar work

I just started the urge work, I’m curious as to why Brooke says to make a plan 24 hours before hand?

I typically plan my day 1st thing in the morning after I have assessed the day before so that I can make it as realistic as possible.

I feel like this way has helped me make better choices daily, which I think is the reason Brooke suggests the 24 hour thing.