Most of us here in NY (can't really say about other area's) have a set number of "weather days" allocated in our school calendar. For our district, it is 3. If we use less than 3 days for snow days, then we get 3 days off added in the spring. If we use 3 days, then our calendar stays as is. If we use MORE than 3 snow days, the we have to make those days up by having school on days that were originally designated for breaks. For our school, spring break is March 29, 30, 31, and April 1 and 2. If we use extra snow days, we have school on march 29, then 30, and then 31 if necessary. So, if we used 6 snow days instead of the 3 that are allotted, we wind up only having a four day weekend for spring break instead of a full week.