Eid Mbaarik.......divided or united?

Eid Mubarak to all Muslims. May Allah bless Muslims with forgiveness and happiness.

Eid is meant to be showing the solidarity and unity among Muslims. But I wonder if we see it in that way. For every Muslim fasting is during the month of Ramadan and Eid at the end of Ramadan. However for some of the Muslims, today is Eid where as for the others tomorrow is Eid.

Is this really the way it should be? will the Muslims always be celebrating our Eid on different days. Will we see a day Muslim Ummah celebrate Eids on a single day, showing ourselves as united rather than divided?
Eid Mubarak once again.