PLaw,
Here in CA (at least in my county), schools are closed from Dec. 20 thru Jan. 2. It IS called Winter Break. Although I am at a year round school, the traditional schools get the same dates off for Christmas. It's always a two week break for us, and we never end or begin our break in midweek. It's always two consecutive Mondays - Fridays.
Our Spring Break is in April, and not any longer the week of Easter. Every now and then, it falls the week of Easter. Although, myself, being year round, do not get a spring break, unless I take some personal vacation time in that period. Yet, when our school was traditional, I cannot tell you how many times parents will call the school and be shocked that our break wasn't the week of Easter. We'd have to explain that it was a "Spring Break" not an Easter break.
TIS