The longest play is 24 hr 20 mins and 2 secs and was achieved by Vickrant Mahajan (India), in Jammu, India, from 13 to 14 August 2015.
A troupe of nine actors performed in "Yes Thank You Universe - A Tale of Two Atttitudes" written especially for this attempt by Vickrant Mahajan himself. It was achieved as part of his attempt to spread the idea of "Super Positivity".
http://www.guinnessworldrecords.com/world-records/longest-play-