Coptic Easter Sunday celebrates the end of Lent and when Mary Magdalene found Jesus tomb empty. It is celebrated when Orthodox Easter is.
Modern day celebrations include egg decorating and hunting with the egg representing life as Christians believed Jesus achieved when he wasn't found in the tomb.
Egypt uses the Julian Calendar to tell when Easter is which makes it fall later than the western churches from April 4th to May 8th. Of course this holiday is still dependent on Passover to know when it will occur.