Quill&Steel OS
Fantasy Calendar Maker for Writers & Worldbuilders
Your world doesn't run on January and Monday, so its calendar shouldn't either.
Quill&Steel OS lets you build a custom fantasy calendar with your own months, weekdays, moons and holidays, then see your world's history land on the right day.
Try Quill&Steel OS free for 14 days
Watch the demo
See how to make a fantasy calendar
Name your months, set how long each one lasts, add a week and a moon (or two), and watch every year of your world lay itself out, with your timeline events already in place.
Everything you need
Custom Fantasy Calendar Generator for Complex Worlds
Set the rules of your world's year once, and Quill&Steel OS works out every year after it, and every year before.
Dual moons & lunar cycles
Add as many moons as your sky needs, each with its own cycle length. Their phases show on every day and keep drifting from year to year, so two moons only line up when the math says they should.
Custom months
Name each month, give it any number of days and its own color, and arrange them in any order. Your year is exactly as long as you make it.
Your own week
A five-day week, a ten-day week, or any length you like. Name each day and the calendar grid reshapes itself to fit.
Holidays & festivals
Add feast days, holy days and festivals once. They come back on the same date every year, each with its own color and description.
Eras & the story's present
Label your years with an era, like the Third Age, and set the date your story takes place. The calendar opens on that day, and you can jump to any year, even before year one.
Connected to your timeline
Every dated event from your fantasy timeline shows up on its day. Wars, sieges and reigns that last for months fill in every day they ran.
All in one place
A worldbuilding calendar tool that's part of your world
A standalone calendar generator gives you a calendar. In Quill&Steel OS, your calendar is built in alongside your fantasy timeline, characters, locations, maps, magic systems, cultures, family trees, story planning, and manuscript.
So when a siege begins on the night both moons are full, you can add it to your timeline and see it land on that exact day.
Made for writers and game masters
One calendar for your novel or your campaign
Use it to keep a novel's days in order, plan festivals and magic tied to the moons, or track the in-world date of a long-running D&D or TTRPG campaign.
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Fantasy novels
Know what day it is in your story and what happened the week before.
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D&D & TTRPG campaigns
Track the in-world date between sessions and see which festivals are coming up.
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Moon magic
Check every moon's phase on any day for rituals, curses or even werewolves.
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Fictional time tracking
Keep days, months and years straight across centuries of history.
Start today
Start building your fantasy calendar
Try the fantasy calendar maker free for 14 days.
14-day free trial. No card required.
FAQ
What is a fantasy calendar?
A fantasy calendar is the system of days, weeks, months and years that a fictional world runs on. It can have its own month names and lengths, its own days of the week, one moon or several, and holidays that matter to the people who live there.
How do I make a fantasy calendar?
Start your free trial, open Calendar and click Configure. Add your months and how many days each one has, name the days of your week, then add any moons and holidays. Set the date your story takes place, and Quill&Steel OS lays out every month of the year for you.
Is this a fantasy calendar generator?
Yes. You set the rules of your world's year once, and it generates the calendar for any year you open, with moon phases and holidays already worked out. It doesn't invent month names or holidays for you, because those are yours to create.
Can my world have two moons, or more?
Yes. Add as many moons as you like, each with its own cycle in days. Every day of the calendar shows each moon's phase, and the cycles carry on from one year to the next instead of resetting every new year.
Can months have different numbers of days?
Yes. Each month can be as long or as short as you want, so a 28-day month can sit beside a 40-day one. The length of the whole year is added up for you.
Can I use it for a D&D campaign?
Yes. Build your setting's calendar, set the current in-world date, and move it forward between sessions. Log what happened on the timeline and it appears on that day in your calendar, alongside upcoming festivals and moon phases.
Can I recreate the Calendar of Harptos?
Mostly. You can set up twelve 30-day months and a ten-day week, and add the festival days as one-day months of their own. Leap days that only come every few years, like Shieldmeet, aren't supported yet.
Does the calendar connect to my timeline?
Yes. Any event on your fantasy timeline that has a date appears on that day in the calendar, and events that last for weeks or months fill in every day they ran.
Is the Quill&Steel OS fantasy calendar maker free?
You can try it free for 14 days, with no card required. After that, the fantasy calendar maker is included on every Quill&Steel OS plan. See pricing.