“National Slider Day” is Thursday, May 15, and White Castle is celebrating by giving away free sliders all day long.
White Castle established the unofficial national holiday in 2015, according to WGN, as a tribute to its iconic burgers.
Customers can redeem their free sandwich at any Chicago White Castle location by downloading the White Castle app and entering the code “SLIDERDAY.”
Additionally, a digital coupon will be available on White Castle’s website and social media pages.