Easter Monday
Easter Monday is the day after Easter Sunday and is a holiday in some countries. Easter Monday in the Western Christian liturgical calendar is the second day of Eastertide and analogously in the Byzantine Rite is the second day of Bright Week.
Festivities
Formerly, the post-Easter festivities involved a week of secular celebration, but in many places this was reduced to one day in the 19th century. Events include egg rolling competitions and, in predominantly Roman Catholic countries, dousing other people with water which traditionally had been blessed with holy water the day before at Easter Sunday Mass and carried home to bless the house and food.
Eastern Orthodox (Byzantine Rite) celebration
In the Eastern Orthodox Church and those Eastern Catholic Churches which follow the Byzantine Rite, Easter Monday is known as "Bright Monday" or "Renewal Monday". The services that day, as in the rest of Bright Week, are quite different than during the rest of the year and are similar to the services on Pascha (Easter Sunday) and include an outdoor procession after the Divine Liturgy; while this is prescribed for all days of that week, often they are only celebrated on Monday and maybe a couple of other days in parish churches, especially in non-Orthodox countries. Also, when the calendar date of the feast day of a major saint, e.g., St. George or the patron saint of a church or one's name day, falls during Holy Week or on Easter Sunday, the saint's day is celebrated on Easter Monday.