The day outside time is a holiday. No work is to be done on this day, and it is reserved exclusively for festivities. Some places even allow a second day of no work to recover.
As the name implies they do not consider this day to be a part of a year, they do not consider it a day that even exists. It is an anomalous day that is only there for the purpose of keeping the calendar aligned and there are all sorts of mythology that sprouted up around it.
It is a day without consequences for most things. Crimes, of course, are disallowed, but debauchery and all degrees of merrymaking are allowed and not looked down upon. Were you to see someone in a debased position on the Day Outside Time, your opinion of them would not and certainly should not change. It is a bigger shame to acknowledge the day than it is to go wild.
It is in celebrating the death of the year, and the birth of a new one.