2005年签署变更，2007年变更。。。

https://www.cnn.com/2007/EDUCATION/03/07/extra.daylight.saving/index.html#:~:text=The%20U.S.%20Department%20of%20Transportation,changes%20in%20the%20United%20States.&text=Part%20of%20the%20act%20will,ends%20on%20Sunday%2C%20November%204.