This is well worth supporting (via Maryam Namazie):
Here's some information from the IDAHO website:
In a world where 77 countries punish women, men and children because of their sexuality an International Day Against Homophobia (IDAHO) provides a platform for everyone to make a powerful statement to demand improvements for peoples quality of life overseas and in the UK.
The day can be used to raise awareness of homophobic issues that are negatively impacting on people’s lives and to also showcase success stories where a positive change has been achieved.
IDAHO is an inclusive campaign for individuals, campaigners, voluntary organisations, special interest groups, employers, businesses, politicians and public service providers to get involved and make a difference.
For evidence of why this day is needed, see here and here.