error-free program

Every day correction is made twice, thereby the error can be controlled within a certain limit, the quasi non error realized and larger error caused by accumulating avoided.

介绍了采用单片机来开发时钟芯片，使整个系统能够同时显示年、月、日、星期、时、分、秒，具有自动校时的功能，每天校正两次，使误差控制在一定范围内，实现准无误差，避免了累计所造成的更大误差。