

Many time zones: You get to a new place and look up what time zone you’re in.
Well, sorta — but it’s no effort at all because my timekeeping device (phone) does this automatically.
For me, the time of day is internalized in a way that I think is hard to switch. Same as how I was raised with imperial units — even though I prefer (and use professionally) metric, the intuition can be a little harder to get. But to each their own of course :)
If your baby isn’t super fussy, the transportation difficulty (in our experience) is more in the logistics getting to/from airport, and dealing with other ground transportation. We just flew 5+hrs (coast to coast, US) with a 2mo and a ~3yo, and it was a piece of cake (typing that, I’ve jinxed the return flight…).
We haven’t done international travel with our kids yet, but we will eventually. When I was 2 my family went to Europe — some countries were meh with respect to kids, but Italy (from my folks’ retelling) was fantastic, as there is (or was) a big cultural love for young kids.
YMMV of course, but it’s absolutely doable! Kids — even starting as babies — have personalities, and you’ll get a sense of what’s appropriate with yours. Good luck!