I thought the time change occurred at 2:00 AM, at which time it became 1:00 AM. Your description says the change occurs at 3:00 AM, but your observations support a 2 AM change.
On a Mac since 1984. Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.
