The government has no rules for the public square dance to what time to end

This depends on the local government's own specific regulations. In order not to disturb the people as the principle of it.

Of course, Article 58 of the Law on Punishment for Public Security Administration clearly stipulates that, in violation of the law on the prevention and control of noise pollution in social life, making noise to interfere with the normal life of other people, shall be given a warning; if the warning is not corrected, shall be given a fine of not less than 200 and not more than 500.