Comcast is donating $1.5 million in public service airtime to promote the National LGBT 50th Anniversary Celebration in Philadelphia this July. Comcast is the lead marketing sponsor of the event, according to its organizers.

The PSA is airing this month and next.

The celebration, July 2-5, marks the anniversary of a Fourth of July 1965 demonstration by LGBT activists in front of Independence Hall.

This year, the celebration will include exhibits, concerts, a wreath laying ceremony and a street festival, plus a ceremony at Independence Hall July 4 hosted by comedian Wanda Sykes (Chris Rock Show, Curb Your Enthusiasm), who hosted the White House Correspondents Association dinner in 2009.

Media and technology companies rank among the nation's best when it comes to LGBT workplace equality with many scoring at 100% rate, according to the 2015 Corporate Equality Index.

Those at 100% this year include, AT&T, Apple, Alcatel-Lucent, Cisco, Comcast, Dell, DirecTV, Facebook, Google, Intel, Sony Pictures Entertainment, Sprint, Nextel, Thomson Reuters, Time Warner Cable, Time Warner,The Walt Disney Co., AMC Entertainment and Viacom. The report is a national tool on corporate practices and polices for lesbian, gay, bisexual and transgender employees.

The  2015 survey and report rated 781 businesses for non-discrimination workplace protections, transgender-inclusive health care benefits, competency programs and public engagement within the LGBT community. The survey is administered by the Human Rights Campaign Foundation, where trends and best practices are also measured, and questions range from informational to ratings. 

"In order to achieve a perfect score, a company has to show a deep and serious commitment to treating their LGBT employees fairly and equally on the job,” said Human Rights Campaign president Chad Griffin in a release. “We also look at whether a company is speaking out in the public square to advocate for LGBT equality here in this country and around the world."

Time Warner Cable has been recognized with a score of 100% for the third year in a row.

"This major accomplishment is a testament to and reflection of our ongoing dedication and commitment to diversity and inclusion at Time Warner Cable," said vice president of diversity and inclusion Jerrell Moore in a release.

DirecTV was another company rated at the highest level. 

"We applaud all of the hard work and dedication of our OUT@DIRECTV members this year and look forward to continuing to evolve policies and practices to help ensure an inclusive workplace for our current employees and the future of our company."