Never use =ISLEAPYEAR(29/02/68), because this would first evaluate 29 divided by 2 divided by 68, and then calculate the ISLEAPYEAR function from this small number as a serial date number.
请不要使用 =ISLEAPYEAR(2/29/68)，因为函数会先计算 2 除以 29 再除以 68，然后将此小数作为 ISLEAPYEAR 函数的日期序数进行计算。