@Critter_from_Ozmastery of light and darkness’ darkness has no spesified duration…I presume it doesn’t last forever. Indeed it doesn't! It should have the same duration as the Light option.
— Jeremy Crawford (@JeremyECrawford) March 14, 2017
@Critter_from_Ozwould it also have concentration since it is so similar to the darkness spell and the light feature also has concentration? Yes, concentration is part of an effect's duration.
— Jeremy Crawford (@JeremyECrawford) March 14, 2017
@Critter_from_Oz No problem. And you're welcome!
— Jeremy Crawford (@JeremyECrawford) March 14, 2017