The first baby out is older biologically and chronologically. The time is preserved using UTC regardless- but if you are not using UTC the time must be correctly given in a form denoting ST or DST to compare the two events on the same date. Regardless of how you slice it- the first on earth out is “older” unless you get into esoteric arguments over how to categorize age and time and blah blah. The time of birth however isn’t generally exact. It’s USUALLY measured once the entire baby has emerged from the vagina, usually by someone on staff, and usually they just look at whatever clock is handy- so the “time of birth” may be significant off based on complications delaying looking at the clock, inaccuracies with the particular clock, differences in time or criteria for recording the “time of birth” etc.
Duh it’s the the first one to pass the vaginal canal. Since daylight savings time only affects the daylight, and it reset at 2:00am, the babies were clearly born at night, so it doesn’t apply!
It also matters which baby yelled “first” when they were born, that trumps any timing issue.
It also matters which baby yelled “first” when they were born, that trumps any timing issue.