Liberty Day, known as 'Dia da Liberdade' in Portuguese, is a public holiday in Portugal celebrated every year on April 25th. The day is a commemoration of the Carnation Revolution, a military coup in 1974 that ended the Estado Novo, Portugal's authoritarian regime that had been in place since 1933. The revolution was named such because as the soldiers marched through the streets of Lisbon, ordinary citizens began to place red and white carnations into the barrels of the soldiers' guns, signifying the peaceful nature of this revolution.

During Liberty Day in Portugal, several events are organized throughout the country to celebrate this landmark in their history. These include parades, concerts, and carnation-laden processions. Many people also use this day to pay tribute to those who lost their lives during the Estado Novo regime. The Portuguese flags are raised in public places and important landmarks, symbolizing the nation's gratitude for the precious liberty obtained by the sacrifices of thousands.

Additionally, Liberty Day is not just limited to festivities and remembrances. It is also a day for Portuguese people to reflect on the importance of democracy and freedom, and to acknowledge the dark period in their history in order to prevent such a regime from returning. Schools and public institutions also use this day to educate younger generations about the significance of this event in Portugal's history.