On that day, customers can “Celebrate 31” and buy scoops of ice cream for just $1.31, according to a press release. Currently, a scoop of ice cream from Baskin-Robbins is around $2.79.

Flavors that the chain highlighted as part of the promotion include Pralines ‘n Cream, Jamoca Almond Fudge, Very Berry Strawberry, Berry Fruitful Greek Frozen Yogurt, Dulce de Leche, Pink Bubblegum, and Watermelon Splash.

“We’re excited to help our guests kick off the summer season with our ‘Celebrate 31’ promotion on May 31 and offer them a special lineup of flavors including Berry Fruitful Greek Frozen Yogurt and Watermelon Splash that they can enjoy during the warm summer months,” said Carol Austin, vice president of marketing at Baskin-Robbins, in a statement.

The move comes as the CEO of Dunkin’ Brands (DNKN), which owns Baskin-Robbins, saw his pay slashed last year. As Fortune reported, CEO Nigel Travis’ pay fell by half in 2015 as the company’s comparable sales growth slowed down at Dunkin’ Donuts. Notably, the donut and coffee chain regularly accounts for about 80% of the company’s total sales and Baskin-Robbins accounts for the rest.

In 2015, Dunkin’ Brands opened 55 new Baskin-Robbins locations around the world.