There's the Soviet Calendar and the Juche Calendar, both tried and dropped in favor of going back to the same standard as the rest of the world.
The Soviet Calendar was the more experimental of the two. They wanted to move away from a seven day week and to a five day week, assigning everyone one random day off in order to have a constant industrial schedule for their factories. This idea was unpopular, primarily because people wanted to have the same day off as their family and friends instead of a random assignment, and after over a decade of trying and not really being able to convince anyone to adopt the schedule the Soviets dropped the idea.
The Juche calendar just set year zero to Kim Il Sung's birthday. KJU dropped it, presumably for boring standardization reasons, although every Western news article about it says that it was some kind of cultural power grab in the way that they like to do about everything that happens in the DPRK.
