Custom calendars

A custom calendar lets a timeline date things the way a world of your own does: "3 Frostfall 3019" instead of "Day 1,094", "Midyear's Day 1420", "T.A. 3019" or "19 BBY". You give it its months, any days that belong to no month, leap years if it has them, and eras if it numbers its years from events. A calendar is a thing of its own: you keep it in your account or a team, and many timelines can use the same one. Creating or changing a calendar needs a Pro or Team plan; choosing one for a timeline does not. This article covers where calendars live, setting one up, writing dates in it, how they read, and changing, deleting or transferring one.

Where calendars live

A calendar belongs to whoever owns the timelines that use it: your account, a team, or the site. Each has one set of calendars, and every timeline it owns can use any calendar in that set. Because timelines share a calendar, a world's timelines keep the same months and read the same dates.

A team's calendars are shared by its members. Its contributors, admins and owner can add and change them; a Member can only choose from them. On someone else's timeline you choose from its owner's calendars, and you can add one only if you could add calendars to that owner's set yourself. Otherwise the form says that only the owner can add calendars.

The Calendars page

Open Calendars under Timelines in the dashboard. Its tabs are Mine, Team and Site: Team appears when you belong to a team, with a menu to choose which one, and Site only for the site's admins. Under the tabs a line counts the calendars the set holds against its limit, such as "3 of 50 calendars used".

The table lists each calendar's Name, a Summary of its months and the length of its year, and what it is Used by. Used by counts the timelines that use the calendar, trashed ones included, and the entities dated in it. The actions menu on a row has two choices:

• Edit opens the calendar to change its name, months, days outside the months, leap years, eras and Epoch date. Changing only the name never re-dates anything, and you can do it on any plan. See Changing a calendar below.
• Delete removes the calendar. It is greyed out while a timeline or an entity uses the calendar.

New calendar, at the top of the page, creates one in the set you are looking at. A set with no calendars yet shows Create your first calendar instead. Calendar names must differ within a set.

Using a calendar on a timeline

A custom calendar is for a timeline that has no real dates. On the timeline's form, turn on Advanced and choose Custom under Date types. The Choose a calendar dialog opens and lists the calendars of the timeline's owner; pick one. Under the list, New calendar… sets up a new one (on the Free plan a notice about the paid plans shows instead). If the owner has no calendars yet, choosing Custom opens the editor straight away. Cancel leaves the timeline as it was.

Once you choose, the timeline counts from an epoch of its own instead of the Gregorian calendar, and a blank start or end switches to the calendar. The Calendar row on the form then shows a select with the owner's calendars and, under it, a summary of the one in use:

• choose another calendar from the select, or New calendar… at the bottom of it;
• Manage calendars, beside the row's label, opens the Calendars page in a new tab, so what you typed in the form stays where it is;
• Remove calendar takes the calendar off the timeline. It can't be removed while the timeline's start or end, or any item, is still dated in it.

Choosing a calendar takes effect when you save the timeline. A calendar you make with New calendar… is different: it exists the moment you create it, even if you then cancel the timeline's form. Under Epoch, the form keeps Counting and the Epoch name; the Epoch date belongs to the calendar (see below).

Months

Name the calendar, then list its months under Months: a name and the number of days in each, from 1 to 999. A calendar has between 1 and 36 months, and every year has the same months in the same order. Month names must differ from each other.

Days outside the months

Some calendars have days that belong to no month, like the Shire's Midyear's Day or the complementary days that close a French Republican year. Add them under Days outside the months: name each one and place it before the first month or after any month. Several days can sit in the same place, in the order you list them; there can be up to 36. A date on one of them reads as the day's name and the year: "Midyear's Day 1420". Their names must differ from each other and from the months.

Leap years

Turn on Leap years if some years are longer. Choose the Month that grows and how many Extra days it gains in a leap year, then the cycles, written the Gregorian way: every 4 years, except every 100, except every 400. Each cycle must be a larger multiple of the one before, up to four cycles. An Offset shifts them when the leap years don't fall on multiples of the first cycle: with every 4 years and an offset of 1, years 1, 5, 9 and so on are leap years. The dialog spells the rule out in words underneath, so you can check it.

The leap month's extra days exist only in a leap year. A day outside the months can be marked Only in leap years, so it appears in leap years alone, like the Shire's Overlithe. If that day is all a leap year adds, choose No month grows as the Month that grows.

Eras

Use Eras if the world numbers its years from events: "T.A. 3019" in the Third Age, "4E 201" in the Fourth Era, "19 BBY" before the Battle of Yavin. Each era has:

• a Name, and an Abbreviation if it has one (up to 12 characters). A label uses the abbreviation when there is one, the name otherwise.
• the year it Starts in, counted in the running year (below).
• what it Counts: Up from its start, so its first year is year 1, or Down to the next era, so its last year is year 1, as BC counts down to AD.
• where its Era word goes: Before the year (T.A. 3019) or After the year (19 BBY).

List eras in time order, up to 36. Each era runs until the next one starts, and the last runs on to running year 1,000,000 (below). An era that counts down needs an era after it to count toward, so the last era always counts up. The first era can leave its start empty if it counts down: it then covers every year before the next era, the way BC covers everything before AD. There is no year 0 in an era. Two eras can't share a name, or read alike through their abbreviations.

The running year

Underneath any eras, a custom calendar counts its years in one plain running number. It has a year 0, and the years before it are negative: year −1, −2 and so on. It runs from −1,000,000 to 1,000,000. Dates without an era are written in it, and so are an era's start year, the epoch date's year and the leap offset.

When a calendar has eras, every running year from the first era's start on falls in exactly one of them, and is shown in it: in a calendar whose Third Age starts in running year 4032, year 4032 reads T.A. 1. Years before the first era belong to no era and read as plain numbers.

The epoch date

A timeline with a custom calendar counts from an epoch, as any timeline without real dates does. Counting and the Epoch name are on the timeline's form, under Epoch, and work as described under Counting from an epoch in Dates, BCE and fuzzy dates.

The Epoch date is not on the timeline. It is part of the calendar, below the months, days outside the months and eras in the editor, and it says which day of the calendar relative dates count from and where the calendar sits in time. That is what makes "year 100, month 3" the same moment on every timeline that uses the calendar. It is always a day inside a month, never a day outside the months.

Changing the Epoch date moves the whole calendar against the epoch, for every timeline that uses it: dates written in the calendar move, relative ones stay where they are.

Writing a date in it

Items, and the timeline's own start and end, can then be dated in the calendar. A new date field starts out in the calendar. With Advanced on, the date field's Calendar picker shows it under its name, or as Custom calendar, beside Relative, which still works for dates counted from the epoch.

A date in the calendar starts with its year and, when the calendar has eras, an era beside it; choose No era (running year) to write the running year instead. The month list holds the months with the days outside the months in their places between them. Stop at the year or the month if that is all you know, or add a day, and then add a time to the minute. A day outside the months takes no day number. Uncertainty works as for any date: see Saying how sure you are in Dates, BCE and fuzzy dates.

An era's years run from 1 to its last year, so a year past the end of its era is refused. In an era longer than a million years, the years past its millionth can only be written as running years, with No era. The leap day and a day only in leap years are offered only in a leap year.

Entities can be dated in a calendar too. In an entity's edit form, turn on Advanced and choose the calendar in the Calendar select; the entity's dates are then in that calendar only. See Dating an entity in a calendar.

How dates read

Every date in the calendar reads with the calendar's own names, in every language: "3 Frostfall 3019", "Frostfall 3019", "Midyear's Day 1420", or just the year. On a calendar with eras, every date reads in the era its year falls in, whether it was written with an era or not. In the viewer, the axis, the cursor and every label use the calendar, and each reader can switch to relative time instead under Date display.

Changing a calendar

Open the Calendars page, then Edit in the calendar's actions menu. Changing a calendar re-dates everything written in it, on every timeline that uses it: rename a month and every date in it reads with the new name. Dates stay attached to their month, day or era, so moving or reordering months, days outside the months or eras moves the dates written in them, and moving an era's start moves the dates written in that era with it. When eras change, a date written in the running year keeps its year and only reads differently. Changing the Epoch date moves the calendar as described above.

When timelines use the calendar, a line above Save says how many will be re-dated. There is no separate confirmation: the change is applied to all of them together, or to none.

A change that would leave a date in a month, on a day or in an era that no longer exists, or in a year past the end of its era, is refused when you save. A dialog titled "This change doesn't fit everything that uses the calendar" lists, timeline by timeline, the items and the timeline start or end to re-date first, each linking to where you can fix it. Anything on a timeline you can't open is counted instead, with a note to ask its owner. Nothing is saved while it is refused, and your changes stay in the editor.

Without a paid plan, Edit shows the calendar read-only, with a notice in place of Save.

Starting from another calendar

To reuse a calendar, open New calendar or Edit and choose Start from a calendar at the bottom of the editor. It lists your calendars and those of your teams; pick one and the editor fills in everything except the name: the months, days outside the months, leap rule, eras and Epoch date. Give it its own name, change what differs, and create it.

Removing and deleting a calendar

Remove calendar, on a timeline's form, only takes the calendar off that timeline. The calendar stays in the set, and other timelines keep using it.

Delete, on the Calendars page, removes the calendar for good, and is available only while no timeline or entity uses it. A timeline in the trash still counts, so delete it for good, or restore it and give it another calendar, first. For an entity, change its calendar to another one, or to None (real-world dates), first.

How many calendars

A set holds up to 5 calendars on the Free plan and 50 on Pro and Team. Creating a calendar past the limit is refused. Deleting one makes room again.

Transferring a timeline

A timeline that is transferred brings its calendar with it. If the person receiving it already has a calendar with the same name and the same definition, the timeline uses that one; otherwise the calendar is added to their set. If that would take them past their limit, they have to delete a calendar before accepting.

If the plan lapses

Everything keeps working. Calendars stay, timelines keep using them, and dates in them can still be added and edited. You can still choose a calendar for a timeline and rename calendars. Only creating a calendar, or changing one (its months, days, leap years, eras or Epoch date), needs a paid plan again.