LOL. Yes thanks a bunch. In researching trees, this becomes very interesting. There are 3 models:
1. Chill hours counts every hour from 45 degrees and below (I like this one, it is much simpler).
2. Chill hours counts every hour from 45 degrees down to and including 32 degrees.
3. The Utah model (probably for areas where it is usually way colder than the South US),
- Utah Model
1 hour below 34 degrees F =0.0 chill unit
1 hour 35-36 degrees F =0.5 chill units
1 hour 37-48 degrees F =1.0 chill units
1 hour 49-54 degrees F =0.5 chill units
1 hour 55-60 degrees F =0.0 chill units
1 hour 61-65 degrees F =-0.5 chill units
1 hour >65 degrees F =-1.0 chill units
Since I live where it has 30+ days of over 100 degrees a lot of summers, the Utah model definitely would not work. The simplest will be hours at 45 degrees and below. I found some apple trees that require 250 chill hours. In looking at Frost days I recorded 10 last year and, whawho, so far 16 this year. But not sure how Frost days are calculated.