E.g., Your stand-up is from 9-930a. After which you can't start anything substantial because 'lunch is coming,' but that's 2.5 hours away (assuming you lunch at noon).
I like morning stand-ups, but a big problem is that if the stand-up is at 9, I start winding down whatever I'm doing around 8:30, and I don't start new tasks after 8-8:30. Multiply the loss by the entire team every day and that's potentially a big loss of time. And because everyone's schedule is different, there's really no place to put the meeting that avoids the problem.
The benefits of a well-run standup can outweight this productivity cost, but it's a real cost that needs to be considered.
I guess this does presume that everyone wraps up at about the same time every day, which I've generally found to be the case, but may not work well with widely distributed workers or places where people actually practice a wider range of work hours.
Team members report on what they did that day, but seldom think about the things they are going to get done next and the things that are preventing them from getting started on the next thing, which in my opinion, are the more important things to focus on.
We had a huge problem with non-delivery people scheduling meetings willy-nilly, just because people's calendar's were free.
I've put the kibosh on that, as much as possible, especially in the afternoon.