Each 'Eid is a Day of peace.
When a Muslim establishes peace within his heart by obeying the Law of Allah and leading a disciplinary life, he has certainly concluded a most invioble treaty of peace with Allah.
Once a person is at peace with Allah, he is at peace with himself and, consequently, with the rest of the universe.
So when he celebrates the 'Eid in the right manner, he is actually celebrating the conclusion of a Peace Treaty between himself and Allah, and this marks the 'Eid as a Day of Peace.
That is the proper meaning of an Islaamic 'Eid: a Day of Peace and Thanksgiving, a Day of forgiveness and moral victory, A Day of Good Harvest and remarkable Achievements, and a Day of Festive Remembrance. An Islaamic 'Eid is all this and is much more; because it is a Day Of ISLAAM, a Day of Allah.