The Freedom From Religion Foundation has set up a big, neon "'A' Is for Atheists" display at Daley Plaza, next to a Nativity scene. View Full Caption DNAinfo/Darryl Holliday

DOWNTOWN — Add atheists to the groups putting up holiday displays at Daley Plaza.

The Freedom From Religion Foundation has set up a big, neon "'A' Is for Atheists" display at Daley Plaza, between a giant Hanukkah menorah and a Nativity scene.

Signs explaining the display say it's to celebrate the pagan holiday of the winter solstice, "the birth of the unconquered sun," but also the Bill of Rights in the U.S. Constitution, "which reminds us there can be no freedom OF religion, without having freedom FROM religion in government."

"If the government is going to open up a public forum to religion, then it has to permit the non-religious — nearly 20 percent of our nation today — to express our point of view as well," said Dan Barker, the group's co-president.

This "'A' Is for Atheists" display will be sharing time and space with the Nativity scene at Daley Plaza throughout the yule season. View Full Caption DNAinfo/Darryl Holliday

According to Tom Cara, director of the Metropolitan Chicago Chapter of the foundation, an attorney for the group worked to secure a place for the display at Daley Plaza. The group simply filed for a permit to put up the display last spring, and it was reviewed and approved in October for a period from Nov. 26 to Dec. 29, mayoral spokesman Tom Alexander said.

Similar displays have gone up this season at the Illinois capital in Springfield and the Wisconsin capital in Madison, where the foundation is based.

The winter solstice, the shortest day of the year, occurs Dec. 21, while the Bill of Rights was ratified on Dec. 15, 1791.

While this is the first year for the atheist display, a Nativity scene has been erected each year at Daley Plaza for nearly three decades after surviving legal challenges.