My colleague and I started as postdocs this year in a US lab.
Recently, we respectively decided to go to a conference and a workshop. The conference was planned since a long time for my colleague, so before the beginning of their postdoc. As for me, I registered for a 3-days workshop at my host institution (not in the US) after the beginning of my postdoc. I asked my PI before registering and I registered because the workshop will bring me additional technical knowledge that I want to use in the future. However, I probably won't need it for the first article of my postdoc.
When I talked with my PI recently they mentioned days off and I realized they expected me to take some to attend the workshop. I asked my colleague, and they had to take days off too to go to their conference.
To give more information, I am a modeler, so I spend my time programming. I work alone on the project, so I don't have short deadlines with fellow coders. My colleague and I do not have a teaching or supervising load. I am currently hosted by the university that is organizing the workshop, so I have no travel, accommodation or registration fees.
I have studied in European countries (Master and PhD) where conferences and workshops are considered work and as such you don't need to take days off. But is it normal in the US?