Calendar Editor

Create custom calendars or modify existing ones. Access from Settings → Module Settings → Calendaria → Open Calendar Editor.

Overview

12 tabs across color-coded groups:

Group	Tabs
Core (pink)	Overview, Display
Structure (green)	Months, Weeks, Years, Time
Features (orange)	Festivals, Eras, Cycles, Moons, Seasons, Weather

Editor Navigation

Overview Tab

Configure calendar identity and selection.

Calendar Selector

Calendar Dropdown. Select an existing calendar template or custom calendar to edit (auto-loads on selection)
Duplicate Calendar. Create a copy of the currently loaded calendar
Create From Scratch. Start a fresh blank calendar

Calendar Identity

Name. Display name for the calendar (required)
Description. Optional notes about the calendar

System Sync

Only shown when the active game system is PF2E or SF2E.

Date Theme. Selects the theme reported to the system’s World Clock and stored on the calendar as metadata.luxonSync.theme. Options reuse the system’s own date-theme labels (AR, IC, AG, CE). Calendars with no compatible theme hide the system’s in-game Show Clock button.

Display Tab

Configure date and time formatting throughout the UI. Each format field shows a live preview below the input using sample calendar data. Invalid format strings get a red border and error message.

Token Reference button opens a dialog listing all available format tokens.

[!TIP] See Format Tokens for the full token reference.

Months Tab

Define your calendar’s months.

Month Fields

Column	Description
Name	Full month name (e.g., “January”)
Abbreviation	Short form (e.g., “Jan”)
Days	Number of days in a normal year
Leap	Extra days added during leap years
Start Weekday	Auto (calculated) or fixed weekday for day 1 of this month
Type	Standard or Intercalary

Month Types

Standard. Normal month in the regular calendar structure
Intercalary. Days outside the normal month/week structure (e.g., festival days between months, the “Day of Threshold” in Renescara). Typically don’t count toward weekday progression.

Month Controls

Custom Weekdays (calendar-week icon): Toggle custom weekday names for this month only
Add (+): Insert a new month after this one
Move Up/Down (chevrons): Reorder months
Remove (trash icon): Delete this month

Custom Weekdays Per Month

When enabled, a month can have its own weekday names independent of the global weekdays. Useful for intercalary periods or months with special day naming.

Zero-Day Months

Months with 0 base days only appear during leap years when extra days are added. Useful for leap-year-only festival periods.

Navigation automatically skips 0-day months in non-leap years
Year view displays 0-day months with reduced opacity

Weeks Tab

Configure the days of the week and optional named weeks.

Weekdays List

Column	Description
Name	Full weekday name. May be left blank
Abbreviation	Short form
Rest Day	Checkbox. Marks weekends for styling and hooks

Weekday Controls

Add (+): Insert a new weekday after this one
Move Up/Down (chevrons): Reorder weekdays
Remove (trash icon): Delete this weekday

Named Weeks

Give each week a name (like “Week of the Wolf” or “Tenday of Stars”).

Enabled. Turn named weeks on/off
Type. How weeks are numbered:
- Year-based. Week numbers continue through the entire year
- Month-based. Week numbers reset at the start of each month
Repeat Cycling. When enabled, named weeks cycle through if there are more weeks in the year than named entries

Named Weeks List

Column	Description
Week Number	Which week number this name targets (with duplicate detection)
Week Name	Full week name
Abbreviation	Short form

[!TIP] Use the [namedWeek] and [namedWeekAbbr] format tokens to display named week names in date strings.

Years Tab

Configure year settings, leap year rules, and named years.

Year Settings

Year Zero. The reference year (year 0 in your calendar’s internal numbering)
Year Zero Weekday. Which weekday falls on day 1 of year zero (determines weekday calculations)
Week Starts On. Rotates the calendar grid so the chosen weekday appears in the first column of MiniCal and BigCal. Display only. Defaults to the first weekday in the Weekdays tab when unset. The underlying weekday cycle order is unchanged.

Leap Year Configuration

Leap Rule. Select how leap years are calculated:
- None. No leap years
- Simple. Every N years
- Gregorian. Standard Earth calendar rules (every 4 years, except centuries, except 400-year marks)
- Custom. Pattern-based rules

Simple Leap Year Fields

Leap Interval. How often leap years occur (e.g., 4 for every 4th year)
Leap Start. First year with a leap day

Custom Leap Year Fields

Leap Pattern. Comma-separated divisibility rules using ! for exclusions (e.g., 400,!100,4 means divisible by 400, OR divisible by 4 but NOT by 100)
Leap Start. First year the pattern applies from

Named Years

Assign display names to specific years. When a year has a name, the [yearName] format token renders it in date strings. Pipe fallback syntax [yearName|YYYY] shows the year name when defined, falling back to the numeric year.

Column	Description
Year	The year number this name applies to
Name	Display name (e.g., “Year of the Dragon”)

Time Tab

Set how time works in your world, including daylight hours.

Time Structure

Hours Per Day. Number of hours in one day (default: 24)
Minutes Per Hour. Number of minutes per hour (default: 60)
Seconds Per Minute. Number of seconds per minute (default: 60)
Seconds Per Round. Combat round duration in seconds (default: 6)

[!WARNING] Changing time settings affects how Foundry’s world time is interpreted. Existing timestamps may display differently.

Non-Standard Time Units

Supports calendars with non-standard time structures:

Variable hours per day. Any number of hours (e.g., 20-hour days)
Variable minutes per hour. Any number of minutes (e.g., 100 minutes/hour)
Variable seconds per minute. Any number of seconds

When using non-standard time:

AM/PM midday calculated as hoursPerDay / 2 instead of fixed 12
Time dial and hour markers automatically scale to the configured hours
All API time methods respect the calendar’s time structure
Sunrise/sunset calculations adapt to the day length

Daylight Hours

Control sunrise and sunset times throughout the year.

Enabled. Toggle daylight calculations on/off. When unchecked, Shortest Day, Longest Day, Winter Solstice, and Summer Solstice are hidden
Shortest Day. Hours of daylight on the winter solstice
Longest Day. Hours of daylight on the summer solstice
Winter Solstice. Month and day of the shortest day
Summer Solstice. Month and day of the longest day

Calendaria interpolates daylight hours between these solstices using a sinusoidal curve.

[!NOTE] Climate zones can override these global daylight settings with per-zone latitude or manual shortest/longest day values. See ClimateEditor zone mode.

Meridiem Indicators

Customize 12-hour time labels for your setting.

Ante Meridiem. Full text for morning hours (default: “AM”)
Post Meridiem. Full text for afternoon/evening hours (default: “PM”)
AM Abbreviation. Abbreviated morning label (default: “AM”)
PM Abbreviation. Abbreviated evening label (default: “PM”)

A and a format tokens use the abbreviated forms. [meridiemFull] gives the full-length labels.

Examples: “Sunward” / “Moonward”, “Before Noon” / “After Noon”

Canonical Hours

Define named time periods like “Dawn”, “Midday”, or “Dusk”.

Column	Description
Name	Period name (e.g., “Matins”)
Abbreviation	Short form
Start Hour	When this period begins (0 to hoursPerDay)
End Hour	When this period ends (0 to hoursPerDay)

Seasons Tab

Define seasonal periods with visual styling.

Season Type

Dated. Seasons have fixed start and end dates (e.g., Spring starts March 20)
Periodic. Seasons cycle by duration in days (e.g., 91 days each)

Season Offset (Periodic Only)

Offset. Number of days into the year before the first season begins

Season Fields

Field	Description
Name	Season name (e.g., “Spring”)
Abbreviation	Short form
Icon/Color	Click the icon button to open an edit dialog for Font Awesome icon and color
Seasonal Type	Canonical season tag (Spring, Summer, Autumn, Winter) used to resolve equinox and solstice anchors and to drive weather integrations. Seasons left unset are skipped when astronomical anchors are resolved

Dated Season Fields

Start Month/Day. When this season begins
End Month/Day. When this season ends

Periodic Season Fields

Duration. Number of days this season lasts

Season Controls

Add (+): Insert a new season after this one
Remove (trash icon): Delete this season
Climate (edit icon): Open the ClimateEditor to configure per-season temperature ranges and weather chance overrides

Astronomical Anchors

Equinox and solstice festivals, and computed notes that anchor to an equinox or solstice, find their target day by matching the Seasonal Type on each season. Equinoxes resolve to the first day of their matching season (spring equinox = first day of Spring, autumn equinox = first day of Autumn). Solstices resolve to the midpoint of their matching season (summer solstice = midpoint of Summer, winter solstice = midpoint of Winter). For seasons defined by month and day, the season bounds are computed from the configured start/end month and day; for seasons defined by day of year, the bounds come from the season’s start and end day values. A season with no Seasonal Type set is skipped, and anchors that reference a type with no matching season do not resolve.

Eras Tab

Define historical periods for your calendar.

[!TIP] Eras may overlap. Use indexed format tokens like [era=1], [eraAbbr=2], [yearInEra=1] to reference a specific matching era.

Era Fields

Column	Description
Name	Era name (e.g., “Age of Humanity”)
Abbreviation	Short form (e.g., “AH”)
Start Year	First year of this era
End Year	Last year of this era (leave blank for ongoing)

Indexed Era Tokens

When multiple eras overlap, use indexed tokens to reference a specific match:

Token	Description
`[era=N]`	Full name of the Nth matching era
`[eraAbbr=N]`	Abbreviation of the Nth matching era
`[yearInEra=N]`	Year within the Nth matching era

Example: If year 1492 falls in both “Dale Reckoning” (era 1) and “Age of Mortals” (era 2), [era=1] gives “Dale Reckoning” and [era=2] gives “Age of Mortals”.

Era Controls

Add (+): Insert a new era after this one
Remove (trash icon): Delete this era

Festivals Tab

Create holidays and special days that appear on the calendar. The Festivals tab is a read-only list; each festival’s metadata lives on its linked journal note.

Add Festival: Create a new festival note and link it to the calendar
Reset to Bundled: Restore the festival notes for bundled calendars back to their template set. Not available on custom calendars.

Festival List

Each entry in the list is a read-only row showing:

Column	Description
Icon	The festival’s icon rendered in the festival’s color
Name	Festival name
Schedule Summary	Readable summary of the festival’s schedule (e.g., month, day, span)

Item controls per row:

Open (pencil icon): Open the festival’s linked note sheet to edit metadata
Delete (trash icon): Remove the note and unlink it from the calendar

Editing a Festival

Festival metadata (name, icon, color, schedule, countsForWeekday, leapYearOnly, leapDuration, description) is stored on the linked journal note. Click Open on a festival row to edit its fields in the note sheet.

[!NOTE] For monthless calendars (like Traveller), festival positioning uses the internal dayOfYear field (1-365) instead of Month/Day. This is set programmatically when importing calendars.

Festival colors render throughout the calendar UI: BigCal grid cells, MiniCal day cells, and intercalary day rows all use the festival’s custom color for borders, backgrounds, day numbers, and the festival icon.

Moons Tab

Add one or more moons with customizable phases.

Moon Fields

Field	Description
Name	Moon name (e.g., “Selûne”)
Cycle Length	Days for a complete lunar cycle (new moon to new moon). Accepts decimal values (e.g., `29.53` for Earth’s synodic month)
Color	Tint color for the moon icon

Reference Date

A known date when the moon was at a specific phase. The moon’s phase on any date is calculated from this reference point.

Year. Reference year
Month. Reference month
Day. Reference day of the month
Reference Phase. Which phase the moon is at on the reference date (dropdown)
Cycle Day Adjust. Offset in days to fine-tune phase alignment (positive or negative)

Moon Phases

Define the phases of the lunar cycle. Each phase covers a percentage range of the cycle.

Column	Description
Icon	Click to pick a phase icon (SVG or emoji)
Phase	Phase name (e.g., “Full Moon”)
Rising	Name for the transitional sub-phase as the moon approaches this phase
Fading	Name for the transitional sub-phase as the moon leaves this phase
Start %	Percentage through the cycle when this phase begins (fixed mode only)
End %	Percentage through the cycle when this phase ends (fixed mode only)
Weight	Relative likelihood of this phase in Randomized mode (minimum `1`). Replaces Start %/End % columns when mode is set to Randomized. Higher weight means the phase occupies a larger share of the cycle

Phase Slider

Interactive visual slider showing all phases as colored segments. Syncs bidirectionally with the Start %/End % number inputs.

Moon Phase Slider

Drag handles between phases to adjust boundaries. Adjacent phases push to maintain a 1% minimum gap.
Double-click a phase segment to normalize it to an equal share (100% / number of phases).
Click percentage labels to toggle between percentage and days display.

[!NOTE] The phase slider and the Start %/End % columns are hidden when the moon uses Randomized phase mode. A Weight column replaces them, controlling each phase’s relative likelihood.

Moon Brightness

Brightness fieldset for each moon controls illumination contributed to nighttime scenes:

Brightness Max. Range slider (0 to 0.3) controlling maximum illumination at full moon
Default: 0 (no illumination)

Moon illumination follows a cosine curve based on phase position. Multiple moons sum their contributions, capped at 0.3 total. See Moon Phases: Moon Brightness and Scene Ambience for details.

Phase Mode

Control how the moon’s phase is determined on each date.

Phase Mode. Dropdown with two options:
- Fixed (default): Phases follow a deterministic cycle based on the cycle length and reference date. Phase boundaries are defined by Start %/End % values.
- Randomized. Phases are determined by a seeded PRNG, producing erratic, non-cyclical moon behavior. Useful for chaotic or magical moons (e.g., Warhammer’s Morrslieb).

Randomized Mode Settings

When phase mode is set to Randomized, additional controls appear:

Seed. Integer seed for the random number generator. The same seed always produces the same phase sequence. Click the dice button to generate a random seed.
Cycle Variance. Range slider (0 to 1) controlling how much the moon’s effective cycle length deviates from its base cycle length. At 0, the randomized cycle stays close to the base length. At 1, cycle lengths vary widely.
Phase Weight (per phase). Number input (minimum 1) in the phases table. Weight controls each phase’s share of the cycle. All phases at weight 1 produces a uniform distribution; doubling a phase’s weight doubles its likelihood of appearing.

Anchor Phases

Guaranteed phase overrides on specific dates. The moon is always at the specified phase on that date regardless of randomization.

Column	Description
Year	The year this anchor applies to (leave blank to apply every year)
Month	Which month the anchor falls in
Day	Day of the month
Phase	Which phase the moon is forced to on this date (dropdown of the moon’s defined phases)
Reset Cycle	Checkbox (fixed-mode moons only). When enabled, restarts the phase cycle from this anchor point instead of just overriding the phase for one day

Add Anchor. Add a new anchor phase entry
Remove (trash icon): Delete an anchor phase

[!TIP] Anchors with a blank year recur annually. For example, setting “Full Moon on month 1, day 15” with no year ensures the moon is always full on that date every year.

Eclipse Settings

Configure eclipses per moon. Eclipses occur when the moon aligns with the calendar’s nodal window model: solar eclipses at new moon during nodal alignment, lunar eclipses at full moon during nodal alignment.

Eclipse Frequency Mode. Dropdown controlling how often eclipses occur:
- None (default): Eclipses disabled for this moon
- Rare. Infrequent eclipses
- Occasional. Moderate eclipse frequency
- Frequent. Eclipses occur often
- Custom. Manually specify the nodal period (see below)

Custom Eclipse Fields

When frequency mode is set to Custom:

Nodal Period. Number of days for the moon’s orbital node to complete one cycle. Controls the spacing between eclipse windows. Smaller values produce more frequent eclipses.

Apparent Size

Visible when eclipses are enabled (any mode except None):

Apparent Size. Range slider (0.1 to 2.0) controlling the moon’s apparent angular size relative to the sun. Determines eclipse subtypes:
- Values < 1.0 produce annular solar eclipses (moon too small to fully cover the sun)
- Values >= 1.0 produce total solar eclipses
- Affects whether lunar eclipses are total or penumbral

Moon & Phase Controls

Add Moon (+): Add a new moon
Remove Moon (trash icon): Delete this moon
Add Phase (+): Add a phase to this moon
Remove Phase (trash icon): Delete this phase

Cycles Tab

Create repeating patterns like zodiac signs, elemental weeks, or numbered years.

Cycle Format

Cycle Format. Template string for displaying cycle values using placeholders like [1], [2], etc.

Cycle Fields

Field	Description
Name	Cycle name (e.g., “Zodiac”)
Length	How many stages before the cycle repeats
Offset	Starting offset (which stage is “first”)
Based On	What unit drives the cycle (see options below)

Based On Options

Year. Cycle advances each calendar year
Era Year. Cycle advances based on years within the current era
Month. Cycle advances each month
Month Day. Cycle advances each day of the month (resets monthly)
Day. Cycle advances each day (total days since epoch)
Year Day. Cycle advances each day of the year (resets yearly)

Cycle Stages

Each cycle has numbered stages that repeat in order.

Stage Name. Name for this position in the cycle (e.g., “Year of the Dragon”)

Cycle Controls

Add Cycle (+): Add a new cycle
Remove Cycle (trash icon): Delete this cycle
Add Stage (+): Add a stage to this cycle
Remove Stage (trash icon): Delete this stage

Weather Tab

Configure climate zones and weather conditions. Two-section layout: Season Climate and Zone Climate.

Season Climate

Lists all defined seasons. Click the edit button on a season row to open the ClimateEditor in season mode, where you can configure temperature ranges and weather preset chance overrides for that season.

Zone Climate

Two-column list of all climate zones with inline controls:

Name. Inline-editable zone name
Edit (pencil icon): Open the Climate Editor in zone mode for full configuration
Duplicate (copy icon): Clone this zone below, including presets, season overrides, and preset aliases. The copy inherits a unique ID and a “Copy of ” label
Add (+): Insert a new zone after this row
Remove (trash icon): Delete this zone

Climate Editor

See the full Climate Editor documentation for details on both season mode and zone mode configuration.

Exporting Calendars

Click Export to download the current calendar as a JSON file.

Export Contents

Exported file includes:

All calendar configuration (months, weekdays, seasons, moons, etc.)
Calendar metadata (name, description)
Export version and timestamp
Current date (when exporting the active calendar)

Use Cases

Backup. Save calendar configurations before making changes
Migration. Move calendars between worlds
Sharing. Share custom calendars with other GMs

Filename

Exports use the format {calendar-name}.json with special characters sanitized.

Re-importing

Re-import via the Calendaria JSON importer. See Importing Calendars.

Saving Your Calendar

Click Save Changes to store the calendar. Options:

Set as Active. Checkbox to switch to this calendar immediately after saving (reloads the world)

Unsaved Changes Confirmation

If unsaved changes exist when closing the editor, switching calendars, creating a new calendar, or duplicating, a confirmation dialog asks whether to discard or cancel.

Editing Built-in Calendars

Modifying a bundled calendar saves changes as an override. Delete becomes Reset to Default to restore the original.

Deleting Calendars

Delete behavior depends on calendar type:

Custom calendars. Permanently deletes the calendar
Bundled calendars with overrides. Resets to the original bundled version
Bundled calendars without overrides. Cannot be deleted

[!NOTE] You must save a new calendar before the Delete button becomes available.

Reset Button

Reset clears all current editor data and starts with a blank template. Does not affect saved calendars.

Tips

Start with a bundled calendar close to what you need, then customize
Use the Renescara calendar as a reference for advanced features
Test your calendar before using it in a live game