Since its launch in 2003, Day One has become the primary voice of expertise in New York City on the issue of dating abuse and domestic violence among youth. Day One was founded to provide critical education and direct services to New York City's youth. 

Day One has educated more than 60,000 youth about how to identify and maintain healthy relationships, obtain legal protection when necessary and assist others experiencing abuse. More than 6,000 professionals have been trained to identify relationship abuse among youth and to provide supportive, nonjudgmental guidance to teens. Hundreds of additional young people have been represented in court, received individual or group counseling, guided through a safety planning process or counseled on their legal rights and responsibilities. Through Day One's leadership programs, student have organized awareness projects that have reached over 6,000 students. Day One is also involved in a range of community partnerships and policy initiatives to increase young people's rights related to intimate partner violence.