That is why I suggested it might be done on-line. I have done nothing to change anything, and my Mac G4 did not change today - the old date for time change.
Mac has this option - setting daylight savings time automatically & connected to Apple America time server. So, it will sync automatically no matter how many times Congress chose to change these.
In the old days of course we all had to change our computer dates they did not change automatically - my the seems a lifetime ago.