Today, HBO released the first trailer for Judd Apatow’s two-part, four-hour Garry Shandling documentary, titled The Zen Diaries of Garry Shandling. Set to air next month, the documentary features over 40 of Shandling’s family members and friends, including James L. Brooks, Sarah Silverman, Jim Carrey, Conan O’Brien, Jerry Seinfeld, and more, plus “four decades’ worth of TV appearances, along with personal journals, private letters and candid home audio and video footage that reveal his brilliant mind and restless soul.†In the trailer, Apatow calls Shandling “the most important mentor that I had – but in a lot of ways, he was a mystery to me.†HBO will air the documentary on Monday, March 26th and Tuesday the 27th.