Eid Mubarak means Happy Eid. It's a bit silly, we ALL wish that we had Eid on the same day. It's just one of those things though, nothing we can do. Some mosques think they should do it on the same day as Saudi Arabia, so basically Saudi celebrate according to the sighting of the moon over there, and we do it on the same day as them. However others think they should follow the closest Muslim country (Morocco), or even the sighting of the moon in their own country so will have it the day after.