Shrove Tuesday is a term used in Ireland , the United Kingdom , and Australia for the day preceding the first day of the Christian season of fasting and prayer called Lent . Shrove Tuesday ( also known as Pancake Day , Pancake Tuesday , Fat Tuesday , and Mardi Gras ) is a term used in English-speaking countries , especially the United Kingdom , Canada , Australia , New Zealand , Philippines , and parts of the United States for the day preceding Ash Wednesday , the first day of the season of fasting and prayer called Lent .