Dagen is of Scandinavian origin, derived from Old Norse elements 'dag' meaning 'day', and 'inn' signifying 'inner'. It was popularized during the Viking Age and has since been adopted by other cultures.
The name Dagen experienced consistent popularity with 7 births each year from 2004 to 2007, except for a slight dip to 6 births in 2005. Over these four years, a total of 27 children were named Dagen.