USA has a daylight saving. However, "Arizona state" does not use daylight saving. The birthdays (in winter and spring) of my 2 daughters do not involve with daylight saving complication.

We are now living at Surprise, Phoenix, Arizona, USA
US Mountain Time time (one house ahead of California, coastal states)

My 2 daughters' birth times are Phoenix local time (as verified by birth certificates).

I saw (with my eyes) my first daughter pulled out of my wife's vagina.
I saw (with my eyes) my second daughter pulled out of my wife's belly (C-section).
I cut 2 daughters' umbilical cords臍帶 with a scissor in my hands in the delivery rooms.

First daughter was a easy one.
However, second daughter has medical implications. She has a VSD (a hole in heart). The hole closed by itself several month later after birth. My wife got a pneumonia (hole still in the lung as a scar) during stay at hospital for delivery. Later, second daughter has feeding problem. It took a long time for therapeutical recovery. It is recovering well now. We spent a lot time and energy in second daughter...