Many do; some don’t. For those atheists that do celebrate Easter, they typically only celebrate the non-religious parts of it.
Easter is a festival that occurs in spring-time – in March or April (with the exact date varying from year to year). It is commonly thought of as a Christian festival celebrating the resurrection of Jesus of Nazareth. There are a number of distinct holy days as part of the festival, such as Palm Sunday, Good Friday, and Easter Sunday. Christians celebrate Easter with activities such as attending church services, retelling the story of the resurrection of Jesus, and having a roast lunch. They may also participate in the more modern, secular aspects of Easter, such as eating chocolate eggs.
Most atheists do not take part in the Christian aspects of Easter. Atheists do not believe that any gods exist, thus they do not believe that Jesus of Nazareth was the son of a god. The same scepticism they apply to the existence of a god they apply to the occurrence of miracles – they do not believe that any miracles have ever happened, thus they do not believe that Jesus came back to life 2000 years ago. Since the Christian celebrations around Easter are about celebrating this resurrection, atheists see no point in partaking of them. However, atheists often do participate in the non-religious aspects, such as eating chocolate eggs, and having roast lunches.
Are atheists who celebrate Easter hypocrites?
No. Christians do not have exclusive rights to celebrations at spring-time or to chocolate.
Furthermore, Easter was not originally a Christian festival. This is evident even in the name. The name ‘Easter’ comes from Old English Eostre, which is the name of an Anglo-Saxon goddess. (Other Anglo-Saxon gods include Woden (Odin), Thunor (Thor), and Frig.) Eostre is the Anglo-Saxon goddess of spring, and the Anglo-Saxons would have feasts in her name at spring-time.