if(and(INDEXOFARRAY(SPLIT(C6, "-"), 1) = 22, INDEXOFARRAY(SPLIT(C6, "-"), 2) = 0), 2, if(and(INDEXOFARRAY(SPLIT(C6, "-"), 1) = 22, INDEXOFARRAY(SPLIT(C6, "-"), 2) = 2), 4, if(and(INDEXOFARRAY(SPLIT(C6, "-"), 1) = 22, INDEXOFARRAY(SPLIT(C6, "-"), 2) = 6), 8, INDEXOFARRAY(SPLIT(C6, "-"), 2) - INDEXOFARRAY(SPLIT(C6, "-"), 1))))这段计算的是什么