该数字钟可实现精度误差≤ 1S/天的变精度时钟，并能方便地调节时钟、时间、定时时间等，秩序结构清晰，一看即懂，还可以配编附加一些功能如计数器功能等（扩展键盘）-The digital clock can be achieved precision of ≤ 1S/day variable precision clock, and can easily adjust the clock, time, regular time, the order of structure clear, a loo