The Lagos, Ogun and Oyo State governments have declared Thursday, August 20, work-free to commemorate this year’s Isese Day, with the three states framing the annual celebration as an important expression of Yoruba culture, traditional religion and indigenous heritage, The PUNCH reports.

The declarations mean public servants and other residents in the three South-West states will observe the day as a public or work-free holiday as traditional worshippers gather for prayers, rituals, processions, and other cultural activities.

In Lagos, the government said more than three million people were expected to participate in the celebration, which it described as potentially the largest single gathering of faithfuls of the African Traditional Religion in the world.

The Special Adviser to the Governor on Tourism, Arts and Culture, Idris Aregbe, announced the work-free day in a statement on Wednesday, saying the celebration should not be viewed merely as another holiday.

“Isese is not a relic. It is a living expression of our traditions and a celebration of Yoruba spirituality as an important part of Nigeria’s cultural and religious landscape,” Aregbe said.