ABOUT USPS EID STAMP
Eid here means Eid-e Ghorboon and Eid-e Fetr and definitely not Norouz.
Eid in the above stamp definitely does not mean Norouz. Why? Here is the reason:
In the above document, Eid is defined as:
[This stamp in the Holiday Celebrations series commemorates the two most important festivals-or eids-in the Islamic calendar. Eid al-Adha (celebrated on March 6 in 2001) marks the end of the hajj, the annual period designated for Muslims to make their pilgrimage to Mecca. Eid al-Fitr (celebrated on Dec. 16 in 2001) celebrates the end of the Ramadan fast. Designed by calligrapher Mohamed Zakariya, the Eid stamp features the Arabic phrase "Eid mubarak" in gold against a blue background, which is reminiscent of many great works of Islamic calligraphy. Eid mubarak translates as "blessed festival," and can be paraphrased, "May your religious holiday be blessed."]