Baskin-Robbins used the number 31 to represent its original promise of offering a different ice-cream flavor for every day of the month.
The company was formed in 1945 when Burt Baskin and Irv Robbins combined their separate ice-cream businesses. The founders promoted variety as a central part of the brand, and the 31-flavor idea became one of its best-known marketing features.
The number does not mean that every shop permanently stocks exactly 31 flavors. Individual locations can carry many more options, and available flavors may vary by country, season, and store size. The slogan and number are therefore a branding reference to choice rather than a strict inventory count.
Baskin-Robbins is also associated with its pink spoon, which lets customers sample flavors before buying. That sampling tradition and the 31 concept helped distinguish the chain from smaller ice-cream parlors.