They probably could have occurred within a 24-hour period
New York is five hours behind Scotland. Wakanda is a fictional country, but the map on the MCU Wiki page places it east of Uganda, roughly within the borders of Kenya in our world; that would make Wakanda three hours ahead of Scotland (eight hours ahead of New York).
The attack in New York happened in the morning. If we estimate the time was around 9am - Tony and Pepper are taking a morning run, Peter is on his way to a school field trip - that means it would have been 2pm in Scotland. It's not normally dark in Scotland at 2pm, so the attacks on New York and Scotland don't appear to have occurred simultaneously.
I don't think we can pinpoint an exact time from the news report (24 hour news channels make this difficult), but we can estimate. It was dark outside so it was reasonably late, but not so late that everywhere was closed, so I'd say around 10pm for the attack in Scotland (8 hours after the attack on New York).
The next part gets complicated because it depends on how fast a Quinjet can fly. They travel from Scotland to the Avengers facility (New York state), then from there to Wakanda. The problem is that the Avengers facility and Wakanda are in pretty much opposite directions from Scotland, which drastically increases the distance they have to travel.
If eight hours passed between the attacks in New York and Scotland, then they have less than sixteen hours to do all of that in. Is that possible? Yes, if a Quinjet can fly faster than a commercial airliner. Is a high-tech government jet faster than a commercial airliner? Probably, so let's say yes.
The attack on Wakanda seemed to begin not that long after their arrival, and appeared to roughly coincide with Thanos' arrival on Titan, which would make it all roughly within a 24-hour period (even if the date had changed).
