It's typically the Thursday and Friday before the opening day of the deer hunt. The deer hunt this year starts on October 21 so if history repeats itself, UEA weekend will start on Thursday October 19th (kids will be out of school the 19th & 20th).
Don't hold me to that as I don't have a calendar yet, but for as long as I can remember that is when it is. I don't know if it varies by school district either. I assume most small towns in Utah will have UEA weekend that week (small towns tend to take the hunt VERY seriously) and Jordan School District is also out that week. Granite always seems to do their own thing though so who knows. I will see if I can find a schedule and let you know for sure.