On Pokemondb.net it says to evolve Rockruff from 5-6 pm. It doesn't say anything else. I was just wandering because people say it is only for an event Rockruff.
Not sure which page you're looking at, but the evolution charts say it's the "Own Tempo Rockruff" (maybe this is not clear enough).
This is the event Rockruff -- however, if you breed the event Rockruff you will get more Rockruff with Own Tempo, and all of those will evolve into Dusk Form Lycanroc. So if you know someone with the event Rockruff or Dusk Lycanroc then they could breed it and trade the baby over to you.