These two stamps are 2010 Easter issue of Poland.
Easter is the central religious feast in the Christian liturgical year.According to Christian scripture, Jesus was resurrected from the dead on the third day after his crucifixion. The chronology of his death and resurrection is variously interpreted to be between AD 26 and AD 36. Easter also refers to the season of the church year called Eastertide or the Easter Season. Traditionally the Easter Season lasted for the forty days from Easter Day until Ascension Day but now officially lasts for the fifty days until Pentecost. The first week of the Easter Season is known as Easter Week or the Octave of Easter. Easter also marks the end of Lent, a season of fasting, prayer, and penance.
Easter is a moveable feast, meaning it is not fixed in relation to the civil calendar. The First Council of Nicaea (325) established the date of Easter as the first Sunday after the full moon The date of Easter therefore varies between March 22 and April 25. Eastern Christianity bases its calculations on the Julian Calendar whose March 21 corresponds, during the twenty-first century, to April 3 in the Gregorian Calendar, in which calendar their celebration of Easter therefore varies between April 4 and May 8.
Easter is linked to the Jewish Passover by much of its symbolism, as well as by its position in the calendar. In most European languages the feast called Easter in English is termed by the words for passover in those languages and in the older English versions of the Bible the term Easter was the term used to translate passover.
Relatively newer elements such as the Easter Bunny and Easter egg hunts have become part of the holiday's modern celebrations, and those aspects are often celebrated by many Christians and non-Christians alike. There are also some Christian denominations who do not celebrate Easter.