"Barack Obama Day" will be "observed throughout the state as a day set apart to honor the 44th President of the United States of America who began his career serving the People of Illinois in both the Illinois State Senate and the United States Senate, and dedicated his life to protecting the rights of Americans and building bridges across communities," the article explained.
Senate Bill 55 passed by both state houses with no votes cast against it, according to NBC Chicago.
A vote in March to make the day a legal state holiday failed. The new holiday is commemorative.
"It's incredibly proud for Illinois that the president came from Illinois. I think it's awesome, and I think we should celebrate it," Rauner said earlier this year, NBC Chicago reported. "I don't think it should be a formal holiday with paid, forced time off, but I think it should be a day of acknowledgment and celebration."
Obama celebrated his 56th birthday Friday. Former Vice President Joe Biden wished him a happy birthday on Twitter.
"Your service has been a great gift to the country, and your friendship and brotherhood are a great gift to me. Happy birthday, Barack," Biden tweeted.