National Coming Out Day (NCOD) is an annual LGBTQ awareness day observed on October 11 and October 12 in some parts of the world. Founded in the United States in 1988, the initial idea was grounded in the feminist and gay liberation spirit of the personal being political, and the emphasis on the most basic form of activism being coming out to family, friends and colleagues, and living life as an openly lesbian or gay person. The foundational belief is that homophobia thrives in an atmosphere of silence and ignorance, and that once people know that they have loved ones who are lesbian or gay, they are far less likely to maintain homophobic or oppressive views.
In more recent years, the idea of the "lesbian and gay community" has been largely subsumed into the idea of the LGBT community, and the idea of "coming out" expanded to not only include the voluntary self-disclosure of a lesbian, gay, or bisexual sexual orientation, but also transgender, genderqueer, or other non-mainstream gender identity. Wikipedia