Why do I buy a lot of electronic watches, calendars and so on, and they all go faster and faster, while the time on my mobile phone and computer is always accurate?

Electronic watches and calendars are independent timing devices. Computer and mobile phone time will be automatically corrected by network standard time, so it is very accurate.

It is difficult for an independent timing device to achieve accuracy per minute. Because the reference frequency circuit will be affected by temperature. The lower the reference frequency, the worse the accuracy. The high-precision timing device is equipped with a constant temperature device.