Easter is the most important religious feast in the Christian liturgical year. Christians believe that Jesus was resurrected from the dead two days after his crucifixion, and celebrate this resurrection on Easter Sunday, two days after Good Friday. The year of this resurrection is variously estimated between the years 26 and 36 AD. Many non-sectarian cultural elements, such as the Easter Bunny, have become part of the holiday's modern celebrations, and those aspects are often celebrated by many Christians and non-Christians alike. It is sometimes celebrated in March and sometimes in April based on the lunar calendar.