National Mashed Potato Day is observed worldwide every October 18, celebrating the beloved side dish made from boiled or steamed potatoes that are mashed and typically mixed with butter and milk or cream. The holiday aims to honor mashed potatoes, which have been a staple since at least the mid-18th century, with recipes dating back to Hannah Glasse's "The Art of Cookery Made Plain and Easy." Celebrants often enjoy meals that feature mashed potatoes, whether prepared from scratch or using instant varieties, which became popular in the early 20th century. The day encourages sharing favorite mashed potato recipes on social media with the hashtag #NationalMashedPotatoDay. It is believed that the holiday was initiated by Idahoan Foods or the Idaho Potato Commission, reflecting the dish's significance in American cuisine, particularly during Thanksgiving and Christmas dinners. Various seasonings and condiments can enhance mashed potatoes, making them a versatile dish enjoyed in many cultures.