Talmaara is a worldbuilding workspace with a book editor built into it. Everything in your world shares a single timeline, even across multiple worlds.
Every date you enter — a king's death, a war, an era, a scene in chapter nine — is stored as pure math along the timeline. It doesn't matter that you invented a planet with 19-hour days, a 400-day year, five made-up months, and a calendar that has 5 eras. Underneath, it all reduces to the same math, so everything you write down can line up with everything else on its own.