Which brand of electronic watch is the most accurate, one with digital display?

A real radio-controlled watch will not error by one second in a million years, because the error we are talking about is compared with the standard time, and the radio-controlled watch synchronizes with the standard time every day, as long as the accuracy of the watch itself It is high enough to ensure that there will be no one-second error between two synchronizations (general radio-controlled watches can guarantee that the error is less than 0.5 seconds within 24 hours, and there will be no accumulated error). Although one second in one million years or one second in two hundred thousand years has no practical significance, it is a technical issue that marks the perfection of watch manufacturing. It is said that radio-controlled watches produced in Japan will have an error of one second after hundreds of thousands of years. This shows that the Japanese have not fully mastered the manufacturing technology of radio-controlled watches. The Chinese-made "Caridi" radio-controlled watch is the real "watch without error".