We don't have a "meeting" so much as just an Open House event.
1. It's normally held about 4 weeks after school starts. I think the hours were 4-6.
2. Yes, it's school wide. The only exception is K, because they have a big night 2 days before school starts. Because it's an Open House, it doesn't matter how many kids you have. You just go into your child's classroom anytime between those 2 hours, meet the teacher, look around, and then move onto the other child's classroom.
3. It's fairly well attended. I think out of 23 students last year, I had 20 show up. We have the student's work displayed, and that normally entices them some. I also gave the kids a goody bag if they showed up (I told them ahead of time), so they normally talked their parents into coming.
I've heard of some schools offering door prizes to get parents there. It's sad that we have to do that, but I guess it takes that sometimes.
I think the Open House makes it easier for everyone because it's very informal, it doesn't matter what time you get there (which makes it nice for working parents), and you can visit all your kids' classrooms without missing anything.