Easter Monday, also known as Bright Monday, Renewal Monday, Wet Monday, and Dyngus Day, is the Monday immediately after Easter Sunday.
It is observed by many Christian groups, but primarily by the Eastern Orthodox and Roman Catholic traditions.
It marks the beginning of Easter Week (Roman Catholic) / Bright Week (Eastern Orthodox).
Different cultures observe Easter Monday very differently.
For some, Easter Monday is a solemn remembrance of Christ’s death and resurrection marked by an outdoor procession.
For others, there are Easter egg-rolling competitions. For still others, siblings and/or spouses wake each other up by pouring buckets of water on each other (hence the name “Wet Monday”).
And others celebrate with a large gathering and a polka festival (Dingus Day).
Some of these observances have more Christian symbolism in them than others, but none of them are explicitly biblical.
The Bible does not say anything about what happened on Easter Monday, the day after Jesus’ resurrection.
The Bible does not instruct followers of Jesus Christ to observe Easter Monday, so there is no obligation to celebrate it.
As with many holidays, there is nothing wrong with observing some cultural traditions, but it is important to not allow traditions to detract from the message of the gospel.