Shrovetide is traditionally the time for "spring cleaning," and just as we clean our houses in these days in prepation for Lent, we also "clean our souls" through confession so we can enter the penitential season fresh. Shrovetide is the last two days of "Carnival," an unofficial period that began after the Epiphany and which takes its name from the Latin carnelevare, referring to the "taking away of flesh" (meat) during Lent which begins on Ash Wednesday, the day following Shrove Tuesday. Catholics want to eat while they can and get the frivolity out of their systems in preparation for the somber Lenten spirit to come.
In my home town, we do things our own way, based on the traditions of the Dutch settlers of the 17th century. Today shrovetide, or "fastelavn" in danish, falls on sunday the 14th and monday the 15th, where the horse riders of Dragør and Store Magleby tour the city, toasting the inhabitants, finally hitting the carnival barrel (if not too drunk).