Ha ha ha, funny that we never thought to explain it! How silly of us.
A group hatch is when we all get together in the chatroom at the same time and hatch a Tamagotchi at the same time. There aren't really any rules. You can show up just to chat if you don't feel like hatching anything. Another way to participate is to hatch something on the same day without coming to the chat, and tell us about it later on the boards!
It's not like a 3-2-1 hatch! thing either, we just all sort of pull the tab at around the same time and have a laugh at the same time, so it's okay to show up late and stuff.
You can read some of the threads about group hatches
to better understand how they work. Someone comes up with an idea of a date or a theme, we try to choose a day and time when many people are available, we set up a chart that covers all the time zones for that day and time, and then we all appear in the chatroom! We chat about all kinds of things. It's a lot of fun.
The best way to find out more is to join the next group hatch! We just had one so we don't have anything coming up. Maybe you can join in planning our next hatch?
Come out! It'll be fun.